The Michigan Alcoholism Screening Test (MAST) and the response to a question about heavy alcohol consumption were used to assess the prevalence of alcohol problems in consecutive patients (77 males and 46 females) consulting a general practitioner in an urban area in the South of Italy (Castellammare di Stabia). Alcohol problems, which were defined by a cut-off score of 5 on the MAST and/or by heavy alcohol consumption (corresponding to at least 60 g of ethanol daily for males and 36 g of ethanol daily for females for at least 2 years), were identified in 54 patients [43.9%; 95% confidence interval (CI) 35.0-53.1%], 45 males (58.4%; 95% CI 46.6-69.6%) and nine females (19.6%; 95% CI 9.4-33.9%). The prevalence of MAST positive patients was 32.5% (95% CI 24.4-41.6%) in the total patient sample, 45.5% (95% CI 34.1-57.2%) among males and 10.9% (95% CI 3.6-23.6%) among females. The question about heavy alcohol consumption had a predictive negative value of 97.2% (95% CI 90.2-99.7%) and a predictive positive value of 73.1% (95% CI 59.0-84.4%) in relation to MAST positive patients. It is suggested that general practitioners should incorporate this question about heavy alcohol consumption as a screening question in order to detect alcohol problems and give advice regarding reduction of alcohol consumption.