To test the hypothesis that associative learning is the basis for conditioned courtship, male Drosophila melanogaster were paired with virgin females in the presence of quinine, known to be a negative reinforcer in a learning paradigm independent of courtship. Such "experienced" wild-type males failed to court virgin females and remained refractory to them for 1-2 h. But experienced males from the learning-defective strain, dunce, continued to court females at high levels; and experienced males from the retention-defective strain, amnesiac, failed to demonstrate the wild-type refractory period. Finally, males from the don giovanni strain, defective with respect to fertilized-female conditioning, were conditioned by presentation of virgin females and quinine. Courtship-depressing effects of cis-vaccenyl alcohol, which can be recovered from fertilized females, were confirmed, but no evidence for its role as a negative reinforcer of male courtship was obtained.