Any compound which disrupts the integrity of psychological aspects of performance, in particular, cognitive ability and psychomotor function analogous to the psychological behaviors of routine life, is known to be behaviorally toxic. A significant level of behavioral toxicity will interfere with patient safety and quality of life, and also may be counter-therapeutic by exacerbating the condition that the drug was prescribed for. Now, behavioral toxicity of psychotropic drugs has become one of the main growth areas of psychopharmacological research. Evaluation of the potential of drug-induced behavioral toxicity is important not only to the experimental researcher involved in human psychopharmacology, but also to the clinical practitioner treating psychiatric patients. This article attempts to describe behavioral toxicity of the three classes of psychotropic drugs - benzodiazepines, antidepressants and neuroleptics. After a brief discussion of some methodological issues arising in the investigation of behavioral toxicity, each of these drug classes is reviewed in the context of practical importance rather than purely scientific concern. The last session summarizes some suggestions for future studies on drug-induced behavioral toxicity.