In three sessions the client saw 140 presentations of male slides, received a total of 52 shocks and reached criterion on four of the five slide sets. At this point he reported that the slides were no longer attractive and that he was not noticing attractive males on the street.But since he was still experiencing frequent homosexual fantasies with no apparent external stimulus, the procedure was modified to a paradigm more like Marks and Gelder's(1967). He was instructed to visualize specific fantasies and to signal when he had a clear image, whereupon the therapist administered a shock of short duration on this signal. After two sessions of this the client reported that these fantasies had essentially disappeared.