Motivational interviewing, a strategy to increase motivation for change, was tested as a preparation for residential alcoholism treatment. Consecutive alcoholism admissions to a private psychiatric hospital (N = 28, 21 men and 7 women) were assigned alternately to receive or not to receive a 2-session motivational assessment and interview shortly after intake, in addition to standard evaluation and treatment procedures. Patients who received the motivational interview participated more fully in treatment (as evidenced by therapist ratings) and showed significantly lower alcohol consumption at a 3-month follow-up interview. The beneficial effects of motivational interviewing on outcome were mediated by increased participation in treatment. The extent to which the received treatment conformed to patients' pretreatment expectations was predictive of outcome.