In 2 experiments, the development of adjuvant arthritis (an experimental autoimmune disease) was inhibited by exposing rats to a flavored solution that had previously been paired with injections of cyclosporine (an immunodepressive drug) compared with rats with the same history but exposed to a flavored solution that had previously not been paired with drug injections. In contrast to earlier experiments on conditioned cyclophosphamide effects, rats did not avoid the taste that had previously been paired with drug administration. Thus, conditioned immunopharmacologic effects were not confounded with taste aversion. These observations are interpreted as reflecting an associative learning process that affected the development of an autoimmune disease.