Pavlovian conditioning of the human male sexual response may be involved in the ontogenetic development of sexual interests and may be responsible for individual differences. We attempted to demonstrate Pavlovian conditioning of sexual interests in a nonclinical sample of adult males. Ten participants were exposed to 11 pairings of a slide of a moderately attractive, partially nude female adult (TARGET) and a highly arousing videotape depiction of heterosexual sexual interactions (US). Ten other participants were exposed to 11 presentations of the TARGET alone. Participants exposed to the TARGET-US contingency showed a 10% relative increase in sexual arousal to the TARGET; participants exposed to the TARGET-ALONE contingency showed an 11% relative decrease in sexual arousal to the TARGET. This group difference is interpreted as resulting from both conditioning and habituation.