The present study explores the relations among gender, impulsivity and three health-risk behaviors relevant to young adults (tobacco use, alcohol problems and gambling problems) in a sample of 197 college-age individuals. We sought to determine whether impulsivity is associated with health-risk behaviors in the same ways for men and women. For tobacco use and gambling problems, men were at higher risk than women, and impulsivity was not significantly associated with higher risk. Higher levels of motor impulsivity in men accounted for a significant amount of the gender difference in risk for alcohol problems. That is, impulsivity as measured by the Barratt Impulsiveness Scale (version 11), mediated the association between gender and risk for alcohol problems. For impulsivity as measured by Stop Signal Reaction Time (i.e. response inhibition), gender moderated the association between impulsivity and alcohol problems. Specifically, lower levels of impulsivity were associated with greater risk for alcohol problems in both men and women, but the effect was stronger in men. We speculate that this seemingly paradoxical result might be the result of coping drinking to deal with negative affect associated with behavioral overcontrol. These findings suggest that prevention efforts might well focus on identifying individuals at high risk for alcohol problems, especially males, by assessing response inhibition.