Many medical inpatients have alcohol related problems but evidence of the feasibility of instituting a brief intervention is incomplete. An alcohol counsellor trained nurses on five general medical wards to screen patients routinely for alcohol problems. She counselled appropriate patients using one or two counselling sessions. Efficacy of the counselling was assessed at interview six months following the admission. We found that 19.6% of male and 4.8% of female medical patients were drinking more than 50 units (U) or 33 drinks per week (male) or 35 U or 23 drinks per week (female). Counselling, with one or two sessions led to a reduction from a median of 74 U (49 drinks) per week at admission to 26 U (17 drinks) per week at six months follow-up. A second counselling session after discharge showed no advantage over a single one administered while the patient was in the ward. The barriers to developing a successful alcohol screening and counselling service in medical wards can be overcome provided there is also adequate support and training of the ward nursing staff.