Novel, low molecular weight inhibitors of IMPDH have been discovered through the application of a validated virtual screening protocol. A series of 21 IMPDH inhibitors were used to validate the docking procedure. Application of this procedure to the selection of compounds for screening from an in-house database resulted in a 50-fold reduction in the size of the screening set (3425 to 74 compounds) and gave a hit-rate of 10% on biological evaluation.