In 1986 the Christchurch Psychiatric Epidemiology Study obtained 1498 interviews using the Diagnostic Interview Schedule. Respondents were from a probability sample of adults aged 18-64 years. This article reports results relevant to preventing alcohol problems. The symptoms most likely ever to be experienced were types of heavy drinking (7-22%) and their consequences such as blackouts (13%). Thirty-two percent of men and 6% of women had met criteria for alcohol disorder prior to interview. The predictors of alcohol disorder were gender, childhood conduct disorder symptoms, early drunkenness, family breakdown and age of leaving school. Cohort effects were clear for onset of drunkenness and alcohol problems. The median duration of alcohol problems was at least 10 years, indicating scope for secondary prevention. General practice and hospitals appeared to be the most suitable places for intervention.