Relatively few studies of the psychobiology ofhyperscxuality have been undertaken. Nevertheless, the literature does suggest the possibility of a neurobiology ofhypersexuality. Three cases of hypersexual behavior are presented in the context of neuropsychiatrie disorders, and the literature on this phenomenon is briefly reviewed. These case studies and the literature provide evidence that different brain.systems may play a role in this disorder. Frontal lesions may be accompanied by disinhibition, including impulsive hypersexual response to external cues, ivhile striatal lesions may be accompanied by repetitive triggering of internally generated response patterns. Temporal-limbic lesions may be accompanied by disturbances in sexual appetite itself, including change in the direction of sexual drive. These case studies demonstrate that a neurobiology ofhypersexuality may prove of some heuristic value in the clinic. However, further research is required to consolidate the literature in this area.