This article starts with a history of the development of neuropharmacology in the past century, which began with 4 drugs and now includes more than 100 approved drugs available to a neurologist in clinical practice. Dr. K K Jain, a neurology consultant in Basel, Switzerland, reviews the molecular basis of neuropharmacology with a focus on clinical applications. Mode of action of drugs is explained as drug receptor interaction. Brain imaging, both PET and fMRI, are now being used for study of drug action on the brain in vivo. Therapeutic drug monitoring is important as a guide to maintenance of proper doses and blood levels of some CNS drugs. New technologies such as nanobiotechnology are being applied to development of neurotherapeutics. As the pathomechanism of neurologic disorders becomes better understood, the focus is on development of neuroprotective rather than symptomatic treatments, particularly for neurodegenerative disorders, stroke, and CNS trauma.