In a sample of active drug users, we assessed the associations between frequency of attending a 12-step program, perceived social norms, and social network structure. Participants who reported that most or all of their drug partners attended 12-step groups were over ten times more likely to be frequent attenders compared to individuals who did not go to Narcotics Anonymous (NA). While social network structure of number of cocaine and heroin users and number of members in treatment was associated with frequent attendance, there was no association among individuals who infrequently went to a 12-step program. Individuals who are trying to control their drug use should be encouraged to affiliate with others in recovery or attending a 12-step program.