Fragment based drug discovery (FBDD) involves the evaluation of low molecular weight (MW <300) compound libraries. Screening does not usually involve either binding or functional activity, but rather residence in a protein target such as by high-throughput protein crystallography, SAR by NMR or MS, or surface plasmon resonance spectroscopy. The general principles of FBDD will be discussed as well as a general overview of the use of the technology at Johnson & Johnson.