Following the development of the Readiness to Change Questionnaire described by Rollnick et al., this article reports on the predictive validity of the questionnaire among a sample of 174 male excessive drinkers identified by screening on wards of general hospitals. Relationships between patients' "stage of change" derived from questionnaires administered prior to discharge from hospital and changes in drinking behaviour at 8 weeks and 6 months follow-up are analysed. Allocated stage of change provided statistically significant relationships with drinking outcome. Multiple regression analysis showed that stage of change remained a significant predictor of changes in alcohol consumption when other possible predictors were taken into account. Two methods for allocating stage of change on the basis of questionnaire responses for use in different circumstances, a "quick" and a "refined" method, are described.