The effect of d-amphetamine on the risk-taking behavior of penitentiary inmates was investigated, utilizing a gambling situation involving cigarettes. The experimental situation consisted of choices between alternative gambles involving different amounts of risk. The 29 men served as their own controls, with the number of high-risk choices made by each subject when under drug (10 mg d-amphetamine sulfate, orally) being compared with the number of choices made during his placebo session. The difference was significant in the direction of increased risk-taking under the drug. The results are interpreted as offering tentative support to the hypothesis that d-amphetamine increases risk-taking, although alternative interpretations are provided.