This article describes a phenomenon, persistent sexual arousal syndrome (PSAS), which heretofore has not been noted or described in the sexuality, psychiatric or medical literature. The syndrome is precisely the opposite of female sexual arousal disorder (FSAD), in that the woman's complaint is of excessive and often unremitting arousal rather than of deficient or absent arousal. Five case descriptions are reported, highlighting the essential feature of the syndrome--persistent physiological arousal in the absence of conscious feelings of sexual desire. To date, no obvious hormonal, vascular, neurological, or psychological causes have been identified as underlying the symptoms of any of these patients. The cases are presented in the hope that they will stimulate efforts to investigate the prevalence, etiology, course, and management of PSAS.