This study investigated the relationship between two biologically-based dimensions of impulsivity, "reward drive" and "rash impulsiveness" as well as the related construct of punishment sensitivity in problem gamblers, with and without alcohol problems, and non-problem gamblers. One hundred and ten adults completed self-report measures of problem gambling, hazardous drinking, rash impulsivity, reward drive and punishment sensitivity. Problem gamblers were more rash-impulsive, reward-driven and more sensitive to punishment than non-problem gamblers, even when controlling for co-existing alcohol problems. There was no difference on any personality measure between hazardous drinking problem gamblers and non-hazardous drinking problem gamblers. However, the relationship between impulsivity facets and problem gambling was moderated by gender. Rash impulsivity was most strongly associated with problem gambling in women whereas both rash impulsiveness and reward drive were associated with problem gambling in men. The unusual combination of both heightened impulsivity/reward drive and high punishment sensitivity in gamblers and the differential relationship between impulsivity and problem gambling across gender are discussed. 頲008 Elsevier Ltd. All rights reserved.