During the 1980s Motivational Interviewing emerged as one of the memes of the addictions field. This occurred despite the lack of scientific evidence supporting its utility. In this paper findings of a controlled trial of a brief motivational intervention with illicit drug users (n = 122) attending a methadone clinic are reported. Clients who met the study's inclusion criteria were randomly allocated to either a motivational (experimental, n = 57) or educational (control, n = 65) procedure. Over the 6-month follow-up period the motivational subjects demonstrated a greater, immediate, commitment to abstention, reported more positive expected outcomes for abstention, reported fewer opiate-related problems, were initially more contemplative of change, complied with the methadone programme longer and relapsed less quickly than the control group. There was, however, no difference in terms of the severity of reported opiate dependence and the control group fared better on reported self-efficacy. It was concluded that motivational interventions of the type investigated are useful adjuncts to methadone programmes.