The research literature on the relation between cognitive functioning and alcohol consumption is inconsistent and difficult to interpret. The purpose of this study was to test a causal model that might help reconcile some of these conflicts. The model specifies that aggressivity is an important intermediary mechanism underlying the relation between executive functioning (EF) and alcohol consumption. Participants were 310 (152 men and 158 women) healthy social drinkers between 21 and 35 years of age tested in a laboratory setting. EF was measured with a battery of neuropsychological tests. Aggressivity and alcohol consumption (as well as cigarette and drug use frequency) were measured with self-report and interview formats. Aggressivity played a mechanistic role in the relation between EF and alcohol/drug use for men but not for women. Women evinced some unexpected positive relations between EF and alcohol use. This study serves as a first step in trying to reconcile previous inconsistent findings regarding the relation between cognitive functioning and alcohol use by demonstrating that a better understanding of this relation involves considering aggressivity as an intermediary variable.