A new methodology was employed to study the effects of drugs on human aggressive behavior in a laboratory situation. The effects of not smoking, smoking a low nicotine dose (0.42 mg/cigarette), and smoking a high nicotine dose (2.19 mg/cigarette) on human nonaggressive and aggressive responding was determined. A nonaggressive response, which resulted in the accumulation of money, was continuously available to the subject. Two different aggressive responses were also available: the ostensible subtraction of money from, and the ostensible presentation of a 1-s blast of white noise to a (fictitious) person. Aggressive responding was elicited by subtracting money from the research subjects, which was attributed to a fictitious person paired with the research subject randomly each day. Nicotine, administered with experimental cigarettes, produced dose-dependent decrease in both types of aggressive responding elicited by low or high frequency subtractions of money attributed to another person. Generally, the more aggressive response option, i.e., subtraction of money from another person, decreased more following nicotine administration. Smoking the same doses of nicotine increased nonaggressive monetary reinforced responding. This indicates that the suppressant effects of nicotine on aggressive responding was not due to a non-specific depressant action.