RetroCHEM is a a command-line tool for graph-based, single step retrosynthetic reaction prediction. It offers a variety of options, including SMILES tutorials, SMILES parsing, conversion to MDL MolFile and graph formats, and predicting decomposition reactions. It leverages the Stanford C++ and Armadillo libraries. The Stanford C++ libraries can be found at https://github.com/zelenski/stanford-cpp-library. The Armadillo library can be downloaded from SourceForge at http://arma.sourceforge.net/.