diff --git a/bin/node-sass b/bin/node-sass
index e94c12c77..4139f71d1 100755
--- a/bin/node-sass
+++ b/bin/node-sass
@@ -3,13 +3,13 @@
 var Emitter = require('events').EventEmitter,
   forEach = require('async-foreach').forEach,
   Gaze = require('gaze'),
-  grapher = require('sass-graph'),
   meow = require('meow'),
   util = require('util'),
   path = require('path'),
   glob = require('glob'),
   sass = require('../lib'),
   render = require('../lib/render'),
+  watcher = require('../lib/watcher'),
   stdout = require('stdout-stream'),
   stdin = require('get-stdin'),
   fs = require('fs');
@@ -229,63 +229,41 @@ function getOptions(args, options) {
  */
 
 function watch(options, emitter) {
-  var buildGraph = function(options) {
-    var graph;
-    var graphOptions = {
-      loadPaths: options.includePath,
-      extensions: ['scss', 'sass', 'css']
-    };
-
-    if (options.directory) {
-      graph = grapher.parseDir(options.directory, graphOptions);
-    } else {
-      graph = grapher.parseFile(options.src, graphOptions);
-    }
+  var handler = function(files) {
+    files.added.forEach(function(file) {
+      var watch = gaze.watched();
+      if (watch.indexOf(file) === -1) {
+        gaze.add(file);
+      }
+    });
 
-    return graph;
+    files.changed.forEach(function(file) {
+      if (path.basename(file)[0] !== '_') {
+        renderFile(file, options, emitter);
+      }
+    });
+
+    files.removed.forEach(function(file) {
+      gaze.remove(file);
+    });
   };
 
-  var watch = [];
-  var graph = buildGraph(options);
-
-  // Add all files to watch list
-  for (var i in graph.index) {
-    watch.push(i);
-  }
+  watcher.reset(options);
 
   var gaze = new Gaze();
-  gaze.add(watch);
+  gaze.add(watcher.reset(options));
   gaze.on('error', emitter.emit.bind(emitter, 'error'));
 
   gaze.on('changed', function(file) {
-    var files = [file];
-
-    // descendents may be added, so we need a new graph
-    graph = buildGraph(options);
-    graph.visitAncestors(file, function(parent) {
-      files.push(parent);
-    });
-
-    // Add children to watcher
-    graph.visitDescendents(file, function(child) {
-      if (watch.indexOf(child) === -1) {
-        watch.push(child);
-        gaze.add(child);
-      }
-    });
-    files.forEach(function(file) {
-      if (path.basename(file)[0] !== '_') {
-        renderFile(file, options, emitter);
-      }
-    });
+    handler(watcher.changed(file));
   });
 
-  gaze.on('added', function() {
-    graph = buildGraph(options);
+  gaze.on('added', function(file) {
+    handler(watcher.added(file));
   });
 
-  gaze.on('deleted', function() {
-    graph = buildGraph(options);
+  gaze.on('deleted', function(file) {
+    handler(watcher.deleted(file));
   });
 }
 
diff --git a/lib/watcher.js b/lib/watcher.js
new file mode 100644
index 000000000..c43552190
--- /dev/null
+++ b/lib/watcher.js
@@ -0,0 +1,84 @@
+var grapher = require('sass-graph'),
+  clonedeep = require('lodash.clonedeep'),
+  watcher = {
+    opts: {}
+  },
+  graph = null;
+
+watcher.reset = function(opts) {
+  this.opts = clonedeep(opts || this.opts || {});
+  var options = {
+    loadPaths: this.opts.includePath,
+    extensions: ['scss', 'sass', 'css']
+  };
+
+  if (this.opts.directory) {
+    graph = grapher.parseDir(this.opts.directory, options);
+  } else {
+    graph = grapher.parseFile(this.opts.src, options);
+  }
+
+  return Object.keys(graph.index);
+};
+
+watcher.changed = function(absolutePath) {
+  var files = {
+    added: [],
+    changed: [],
+    removed: [],
+  };
+
+  this.reset();
+
+  graph.visitAncestors(absolutePath, function(parent) {
+    files.changed.push(parent);
+  });
+
+  graph.visitDescendents(absolutePath, function(child) {
+    files.added.push(child);
+  });
+
+  return files;
+};
+
+watcher.added = function(absolutePath) {
+  var files = {
+    added: [],
+    changed: [],
+    removed: [],
+  };
+
+  this.reset();
+
+  if (Object.keys(graph.index).indexOf(absolutePath) !== -1) {
+    files.added.push(absolutePath);
+  }
+
+  graph.visitDescendents(absolutePath, function(child) {
+    files.added.push(child);
+  });
+
+  return files;
+};
+
+watcher.removed = function(absolutePath) {
+  var files = {
+    added: [],
+    changed: [],
+    removed: [],
+  };
+
+  graph.visitAncestors(absolutePath, function(parent) {
+    files.changed.push(parent);
+  });
+
+  if (Object.keys(graph.index).indexOf(absolutePath) !== -1) {
+    files.removed.push(absolutePath);
+  }
+
+  this.reset();
+
+  return files;
+};
+
+module.exports = watcher;
diff --git a/package.json b/package.json
index 7115a33d6..f5c844acc 100644
--- a/package.json
+++ b/package.json
@@ -75,12 +75,14 @@
   "devDependencies": {
     "coveralls": "^2.11.8",
     "eslint": "^3.4.0",
+    "fs-extra": "^0.30.0",
     "istanbul": "^0.4.2",
     "mocha": "^3.1.2",
     "mocha-lcov-reporter": "^1.2.0",
     "object-merge": "^2.5.1",
     "read-yaml": "^1.0.0",
     "rimraf": "^2.5.2",
-    "sass-spec": "3.5.0-1"
+    "sass-spec": "3.5.0-1",
+    "unique-temp-dir": "^1.0.0"
   }
 }
diff --git a/test/fixtures/watcher/main/one.scss b/test/fixtures/watcher/main/one.scss
new file mode 100644
index 000000000..414af5e3f
--- /dev/null
+++ b/test/fixtures/watcher/main/one.scss
@@ -0,0 +1,5 @@
+@import "partials/one";
+
+.one {
+  color: red;
+}
diff --git a/test/fixtures/watcher/main/partials/_one.scss b/test/fixtures/watcher/main/partials/_one.scss
new file mode 100644
index 000000000..b2a72d637
--- /dev/null
+++ b/test/fixtures/watcher/main/partials/_one.scss
@@ -0,0 +1,3 @@
+.one {
+  color: darkred;
+}
diff --git a/test/fixtures/watcher/main/partials/_three.scss b/test/fixtures/watcher/main/partials/_three.scss
new file mode 100644
index 000000000..1846e9ae2
--- /dev/null
+++ b/test/fixtures/watcher/main/partials/_three.scss
@@ -0,0 +1,3 @@
+.three {
+  color: darkgreen;
+}
diff --git a/test/fixtures/watcher/main/partials/_two.scss b/test/fixtures/watcher/main/partials/_two.scss
new file mode 100644
index 000000000..6a3b4ed90
--- /dev/null
+++ b/test/fixtures/watcher/main/partials/_two.scss
@@ -0,0 +1,3 @@
+.two {
+  color: darkblue;
+}
diff --git a/test/fixtures/watcher/main/two.scss b/test/fixtures/watcher/main/two.scss
new file mode 100644
index 000000000..3e9c0fbf9
--- /dev/null
+++ b/test/fixtures/watcher/main/two.scss
@@ -0,0 +1,5 @@
+@import "partials/two";
+
+.two {
+  color: blue;
+}
diff --git a/test/fixtures/watcher/sibling/partials/_three.scss b/test/fixtures/watcher/sibling/partials/_three.scss
new file mode 100644
index 000000000..1846e9ae2
--- /dev/null
+++ b/test/fixtures/watcher/sibling/partials/_three.scss
@@ -0,0 +1,3 @@
+.three {
+  color: darkgreen;
+}
diff --git a/test/fixtures/watcher/sibling/three.scss b/test/fixtures/watcher/sibling/three.scss
new file mode 100644
index 000000000..4e9d1a7e4
--- /dev/null
+++ b/test/fixtures/watcher/sibling/three.scss
@@ -0,0 +1,5 @@
+@import "partials/three";
+
+.three {
+  color: green;
+}
diff --git a/test/watcher.js b/test/watcher.js
new file mode 100644
index 000000000..7c9135e72
--- /dev/null
+++ b/test/watcher.js
@@ -0,0 +1,190 @@
+var assert = require('assert'),
+  fs = require('fs-extra'),
+  path = require('path'),
+  temp = require('unique-temp-dir'),
+  watcher = require('../lib/watcher');
+
+describe.only('watcher', function() {
+  var main, sibling;
+  var origin = path.join(__dirname, 'fixtures', 'watcher');
+
+  beforeEach(function() {
+    var fixture = temp();
+    fs.ensureDirSync(fixture);
+    fs.copySync(origin, fixture);
+    main = fs.realpathSync(path.join(fixture, 'main'));
+    sibling = fs.realpathSync(path.join(fixture, 'sibling'));
+  });
+
+  describe('with directory', function() {
+    beforeEach(function() {
+      watcher.reset({
+        directory: main,
+        loadPaths: [main]
+      });
+    });
+
+    describe('when a file is changed in the graph', function() {
+      it('should return the files to compile', function() {
+        var files = watcher.changed(path.join(main, 'partials', '_one.scss'));
+        assert.deepEqual(files, {
+          added: [],
+          changed: [path.join(main, 'one.scss')],
+          removed: [],
+        });
+      });
+
+      describe('and @imports previously not imported files', function() {
+        it('should also return the new imported files', function() {
+          var file = path.join(main, 'partials', '_one.scss');
+          fs.writeFileSync(file, '@import "partials/three.scss";', { flag: 'a' });
+          var files = watcher.changed(file);
+          assert.deepEqual(files, {
+            added: [path.join(main, 'partials', '_three.scss')],
+            changed: [path.join(main, 'one.scss')],
+            removed: [],
+          });
+        });
+      });
+    });
+
+    describe('when a file is changed outside the graph', function() {
+      it('should return an empty array', function() {
+        var files = watcher.changed(path.join(sibling, 'partials', '_three.scss'));
+        assert.deepEqual(files, {
+          added: [],
+          changed: [],
+          removed: [],
+        });
+      });
+    });
+
+    describe('when a file is added in the graph', function() {
+      it('should return only the added file', function() {
+        var file = path.join(main, 'three.scss');
+        fs.writeFileSync(file, '@import "paritals/two.scss";');
+        var files = watcher.added(file);
+        assert.deepEqual(files, {
+          added: [file],
+          changed: [],
+          removed: [],
+        });
+      });
+
+      describe('and @imports previously not imported files', function() {
+        it('should also return the new imported files', function() {
+          var file = path.join(main, 'three.scss');
+          fs.writeFileSync(file, '@import "partials/three.scss";');
+          var files = watcher.added(file);
+          assert.deepEqual(files, {
+            added: [
+              file,
+              path.join(main, 'partials', '_three.scss')
+            ],
+            changed: [],
+            removed: [],
+          });
+        });
+      });
+    });
+
+    describe('when a file is added outside the graph', function() {
+      it('should return an empty array', function() {
+        var files = watcher.added(path.join(sibling, 'three.scss'));
+        assert.deepEqual(files, {
+          added: [],
+          changed: [],
+          removed: [],
+        });
+      });
+    });
+
+    describe('when a file is removed from the graph', function() {
+      it('should return the files to compile', function() {
+        var files = watcher.removed(path.join(main, 'partials', '_one.scss'));
+        assert.deepEqual(files, {
+          added: [],
+          changed: [path.join(main, 'one.scss')],
+          removed: [path.join(main, 'partials', '_one.scss')],
+        });
+      });
+    });
+
+    describe('when a file is removed from outside the graph', function() {
+      it('should return an empty array', function() {
+        var files = watcher.removed(path.join(sibling, 'partials', '_three.scss'));
+        assert.deepEqual(files, {
+          added: [],
+          changed: [],
+          removed: [],
+        });
+      });
+    });
+  });
+
+  describe('with file', function() {
+    beforeEach(function() {
+      watcher.reset({
+        src: path.join(main, 'one.scss'),
+        loadPaths: [main]
+      });
+    });
+
+    describe('when a file is changed in the graph', function() {
+      it('should return the files to compile', function() {
+        var files = watcher.changed(path.join(main, 'partials', '_one.scss'));
+        assert.deepEqual(files, {
+          added: [],
+          changed: [path.join(main, 'one.scss')],
+          removed: [],
+        });
+      });
+    });
+
+    describe('when a file is changed outside the graph', function() {
+      it('should return an empty array', function() {
+        var files = watcher.changed(path.join(sibling, 'partials', '_three.scss'));
+        assert.deepEqual(files, {
+          added: [],
+          changed: [],
+          removed: [],
+        });
+      });
+    });
+
+    describe('when a file is added', function() {
+      it('should return an empty array', function() {
+        var file = path.join(main, 'three.scss');
+        fs.writeFileSync(file, '@import "paritals/one.scss";');
+        var files = watcher.added(file);
+        assert.deepEqual(files, {
+          added: [],
+          changed: [],
+          removed: [],
+        });
+      });
+    });
+
+    describe('when a file is removed from the graph', function() {
+      it('should return the files to compile', function() {
+        var files = watcher.removed(path.join(main, 'partials', '_one.scss'));
+        assert.deepEqual(files, {
+          added: [],
+          changed: [path.join(main, 'one.scss')],
+          removed: [path.join(main, 'partials', '_one.scss')],
+        });
+      });
+    });
+
+    describe('when a file is removed from outside the graph', function() {
+      it('should return an empty array', function() {
+        var files = watcher.removed(path.join(sibling, 'partials', '_three.scss'));
+        assert.deepEqual(files, {
+          added: [],
+          changed: [],
+          removed: [],
+        });
+      });
+    });
+  });
+});