A series of substances from different pharmacological classes was examined by two different tests for their activity on learning and memory. A concomitant evaluation was performed by use of a one-trial passive avoidance immediately followed by electroshock in mice and the pole-climbing test in rats. Only doses not producing changes in gross behavior (Irwin's test) were used. A facilitating action on all the considered parameters was observed for d-amphetamine, caffeine, L-glutamine, Mg pemoline, phosphorylserine, piracetam, strychnine, and tricyanoaminopropene. A worsening action was found for atropine, cycloheximide, diazepam, and morphine. Chlorpheniramine, diphenylhydantoin, GABA, imipramine, meclizine, mescaline, metrazol, and testosterone showed no or doubtful activity. Our results suggest that the parallel use of these relatively simple tests supplies information that is satisfactory for screening purposes and that has a high degree of predictability as substantiated by literature data.