Volume 95 of "International Review of Neurobiology" focuses on Catechol-O-methyltransferase inhibition, and its clinical application in relation to Parkinson's disease. It includes chapters that cover COMT gene and proteins, L-dopa treatment in Parkinson's disease, the latest research on COMT inhibitors and their clinical applications, as well as future prospects for their use. It also includes up-to-date summary of biochemistry and pharmacology of COMT and its inhibitors; and, preclinical models in COMT inhibitor devlopment. It summarizes transgenic COMT mice - latest information. It covers chemistry of COMT inhibitors and their design with molecular modelling COMT gene and its regulation and relation to dopamine related diseases. It provides role of cofactor SAM regulation in relation to homocysteine. It summarizes nonclinical and clinical safety of COMT inhibitors. It includes future prospects of COMT inhibitors in Parkinson's disease.