Using the Alcohol Use Disorders Identification Test (AUDIT) as the gold standard, the Fast Alcohol Screening Test (FAST) was developed for use in busy medical settings. AUDIT questionnaires were completed by 666 patients in two London accident & emergency (A&E) departments. Using a principal components analysis, as well as sensitivity and specificity indices, a two-stage screening test was developed, using four of the AUDIT items. The first stage involved one item that identified >50% of patients as either hazardous or non-hazardous drinkers. The second stage made use of the other three items to categorize the rest. The performance of this four-item questionnaire was then tested across a range of settings. Opportunistic samples of 100 patients completed AUDIT questionnaires in each of the following National Health Service settings: A&E department, fracture clinic, primary health centre and a dental hospital. It was concluded that the four-item FAST questionnaire had good sensitivity and specificity, across a range of settings, when the AUDIT score was used as the gold standard. The FAST questionnaire is quick to administer, since >50% of patients are categorized using just one question.