This study tests the efficacy of social control, differential association, social learning, and self esteem theories as explanations for the variation in individual levels of illegal drug involvement among a sample of adult incarcerated drug offenders in Iran. The results of path analysis indicate that measures of differential association (with drug-involved peers) and self-esteem had significant direct effects on self-reported narcotics crimes, whereas attachment, belief, and family drug involvement were indirectly associated with variation in level of drug involvement. As a result of its sharply different cultural and religious contexts, Iran presents a unique case for the evaluation of theoretical models developed to explain offending in Western nations. Yet because of its political structure and ideological and religious sensitivity to drug use, there have been few published analyses of drug use and drug offenders in Iran, making this study one of the first of its kind in either Western or Persian-language journals.