A study examined the relationship between deviant sexual arousal, as measured by auditory phallometric stimuli, and psychopathy, as measured by the Psychopathy Checklist-Revised, in 156 incest offenders, 260 extrafamilial child molesters and 123 rapists. Subjects in each category had never been convicted of another type of sexual offense. Rapists were more psychopathic than incest offenders and child molesters. Deviant sexual arousal to auditory stimuli was evident only on the Pedophile Index for child molesters. Child molesters evidenced a significant correlation between psychopathy and the Rape Index and psychopathy and the Pedophile Index. There was a significant relationship between deviant sexual arousal and psychopathy in extrafamilial child molesters. In addition, deviant arousal has been shown to be predictive of sexual reoffense among child molesters and psychopathy predicts sexual and violent recidivism. The article notes the wisdom of clinicians considering these factors when estimating risk of recidivism and determining management and treatment programs. Tables, references