Of 609 male patients seen for sexually transmitted disease, 94 (15.4%) admitted to having had orogenital intercourse; 30 (5%) had practiced it during their last contact. Ten of the 30 patients admitting to fellatio during their last exposure had gonococcal urethritis. Three of these men practiced fellatio exclusively with prostitutes, and their cases demonstrate the inherent risk of oral-to-genital transfer of sexually transmitted disease. All three patients responded favorably to therapy with ampicillin and probenecid.