Previous studies using aversive training tasks have reported that retention is enhanced by post-training administration of epinephrine. This study investigated the effects of post-training administration of epinephrine on retention of an appetitive task. The results indicate that epinephrine can enhance retention performance in an appetitive task of both rats and mice. Pretraining injections of propranolol and phenoxybenzamine, alpha- and beta-adrenergic receptor antagonists, attenuate the memory-enhancing effects of epinephrine. These results are consistent with the view that release of peripheral epinephrine may regulate storage of new information and may mediate memory modulation produced by a variety of treatments.