1. The effects on avoidance acquisition of two nootropic drugs, oxiracetam and piracetam, were tested in mice subjected to five daily 100-trial training sessions in the shuttle-box. 2. Oxiracetam (25 or 50 mg/kg/i.p.) and piracetam (100 mg/kg/i.p.), given before each daily session, improved avoidance acquisition in the good performing BALB/c more than in the poor performing C57BL/6. In both cases avoidance facilitation was evident only if training was preceded by a five-day pretreatment. 3. Combinations of nootropics and methamphetamine increased avoidance responses in C57BL/6 mice more than drugs given separately. Conversely, no interaction occurred in a locomotor activity test. 4. Interactive effects in the learning situation, but not in a test of general activity, were also found when oxiracetam was combined with the anticholinergic agent scopolamine. 5. On the whole, the above results demonstrate facilitation of active avoidance acquisition by piracetam-like nootropic agents, but the neurochemical mechanisms involved in this action are not yet clear.