Only one prior study has examined social competence (SC) in drug addicted individuals. That study of cocaine-addicted individuals found gender differences in SC as well as differences based on the type of comorbid psychiatric diagnoses given. This study attempts to replicate findings from that cocaine study in a sample of opiate-addicted individuals and explores the relationship of SC to short-term treatment response. Gender differences in SC were examined in 28 women and 44 men attending a community methadone maintenance program. The question of differences in SC based on comorbid psychiatric diagnoses and treatment response were examined in a sample of 198 men attending a Veterans Administration methadone program. Women were found to have significantly lower SC than men. No significant differences in SC were revealed based on the presence of specific psychiatric diagnoses. SC was not related to short-term treatment response.