Trials and errors to learning a passive avoidance response were assessed in 63 albino rats injected subcutaneously with d-amphetamine, in amounts ranging from 0–7 mg/kg body weight. Both measures indicated dose-response effects on responding; animals under either low or high doses of d-amphetamine made significantly less errors and took significantly fewer trials to learn the response than did middle dosage animals. The scores of the lower and higher dosage animals did not differ from the nondrug control group. Results are discussed in terms of amphetamine stereotypy.