The purpose of this study was to examine the acute effects of alcohol on aggressive behavior in men and women in a laboratory setting. Participants were 526 (261 men and 265 women) healthy social drinkers between 21 and 35 years of age. They were randomly assigned to either an alcohol or a placebo group. Aggression was measured using a modified version of the Taylor Aggression Paradigm in which electric shocks are received from, and delivered to, a same gender fictitious opponent during a supposed competitive interpersonal task. Aggression was operationalized as the intensity and duration of shocks that participants administered to their "opponent." Overall, men were more aggressive than women. Alcohol increased aggression for both men and women but this effect was stronger for men. This is one of the first laboratory studies to demonstrate that alcohol increases aggression in women.