BACKGROUND: Treatment of drug addiction is complex; hence there is a debate in the field of what is the best approach. An honest desire to stop using drugs is the entry ticket into the self-help programmes Alcoholics Anonymous (AA) and Narcotics Anonymous (NA); these groups are a possible supplement to ordinary treatment. They employ the twelve-step programme and are found in most large cities in Norway and around the world. The usefulness of these groups has been disputed, and few Norwegian treatment facilities have developed a systematic cooperation with them. The purpose of this study was to examine whether the use of self-help groups is associated with higher rates of abstinence two years after participants started attending groups. MATERIALS AND METHODS: 114 patients, 59 with alcohol addiction and 55 with drug addiction, who started in self-help groups after a drug treatment, were approached two years later with a questionnaire. The response rate was 66%; 6 (5%) patients were dead. RESULTS:Intention to treat analysis showed that 38% participated in self-help programmes two years after treatment. Of regular participants, 81% had been abstinent over the previous 6 months, compared with only 26% among non-participants. Logistic regression analysis showed odds ratio = 12.6, 95% CI (4.1-38.3), p