The field of pharmaceutical profiling in drug discovery is described. The pharmaceutical properties of drug candidates determine how much of the drug safely reaches the therapeutic target. Drug candidates often fail in discovery and development due to inadequate properties, resulting in lost opportunities and resources for developing new drugs. Pharmaceutical profiling assays have been developed and implemented to measure the properties of large numbers of drug candidates starting at the earliest stages of discovery. This information is used for informed decisions in drug candidate selection and synthetic optimization. A holistic process of parallel activity and property optimization has emerged in drug discovery. The assays, strategies, and data management associated with pharmaceutical profiling are discussed.