The relationship between personality and substance use disorders was investigated in a community-based sample of 638 individuals who were alcoholic and/or had a drug use disorder, and 1,530 individuals who did not have a substance use disorder. Personality was assessed by the Multidimensional Personality Questionnaire; substance use diagnoses were based on standard criteria as assessed by interview. Data were analyzed using a 3-factor (Gender x Alcoholism x Drug Use Disorder) multivariate analysis of variance. The significant alcoholism main effect was associated primarily with negative emotionality, whereas the significant drag use disorder main effect was associated primarily with constraint. No significant interactions with gender were observed. These findings suggest that the elevated levels of behavioral disinhibition observed with alcoholic individuals may be attributable to a subset of alcoholic individuals who also abuse drags other than alcohol.