I would wager that all biological scientists have paid at least one visit to our good friend PubMed. (If PubMed were a phone contact, we’d all have him on speed dial!) Yes, while we are all familiar with this essential literature-seeking resource, I am sure that many people are less familiar with another one of the fantastic tools at NCBI—PubChem. PubChem, part of the National Institutes of Health’s Molecular Libraries Roadmap Initiative, is a resource that provides information on the bioactivity of small molecules. The number of substance records is currently over 85 million (not too shabby)! The website comprises three databases: PubChem Substance (search names of substances), PubChem Compound (search unique chemical structures), and PubChem BioAssay (search bioassay records). So get ready to expand your circle of online resource friends, folks, as PubChem certainly warrants an occasional visit.