ObjectiveTo evaluate the effectiveness of relapse prevention (RP) and brief intervention (BI) in reducing HIV risk-taking behaviours among injecting drug users (IDU) enrolled in methadone programmes. The hypotheses tested were: (1) that a six-session RP programme would be more effective in reducing HIV risk-taking behaviours than a one-session BI and a non-intervention control condition (C); and (2) that Bl would be more effective in reducing HIV risk-taking behaviours than C.DesignClients of methadone programmes were randomly assigned to either RP, Bl, or C. Follow-up occurred 6 months after pre-intervention assessment and was conducted by independent research assistants who were not aware of subjects' group allocations.SettingConfidential assessment interviews and interventions generally took place at the methadone unit treating the subject.ParticipantsNinety-five IDU enrolled in methadone programmes. Study entry criteria were: injection of any drug in the 6 months before the day of pre-intervention assessment; literacy in English; agreement to HIV-antibody testing for research purposes; and no known diagnosis of a serious mental illness. Eighty subjects were contacted successfully for a 6-month follow-up.InterventionsThe RP intervention was a six-session programme. Each 60–90-min session was conducted individually. The Bl was a one-session motivational interview lasting 60–90 min, accompanied by a self-help booklet.Main outcome measuresAll subjects were administered the Drug Use Scale and HIV Risk-Taking Behaviour Scale of the Opiate Treatment Index and consented to the collection of a capillary blood sample for HIV-antibody testing at pre-intervention assessment and follow-up. At follow-up, the Highest HIV Risk-Taking Behaviour Scale, collateral reports from subjects' sexual partners pertaining to the previous month and urinalysis results for the month before follow-up were collected.ResultsCompliance with interventions was good. Correspondence of self-reports with urinalysis and collateral reports was satisfactory. There were no significant differences between groups in risk-taking behaviours during the month before follow-up. However, there was evidence of a lower rate of needle-risk behaviour (sharing and cleaning) during the heaviest risk-taking month since pre-intervention assessment in the group given RP. There were no indications that Bl was of greater benefit than the usual methadone treatment and neither intervention appeared to reduce sexual risk behaviour.ConclusionsThe results are cautiously interpreted as showing that individual RP programmes decrease the level of needle-risk behaviour during relapse episodes, but further research is required to replicate this finding.