Opium is the most prevalent drug in Iran. There are also evidences indicating that alcohol use is growing during recent years. This article examines some social factors affecting opium and alcohol use among university students. This was performed using the data of a survey on drugs use the sample of which included 5231 male and female students of 21 non-medical state universities from all over Iran. Examined variables include gender, socioeconomic status of the family, religiosity, anomie, educational and occupational expectations and hopes, and the involvement of family and friends in drug and alcohol. These were selected based on the implications of social deviance theories while considering the limitations of a secondary data analysis. The data revealed that all selected variables had significant relationship with both opium and alcohol use. However, the quality of the relationship between independent variables with opium differed to some extent with the quality of their relations with alcohol. The most striking different appeared in differential effect of religiosity and socio-economic status of family on opium and alcohol use.