Previous research may have underestimated physicians' detection rates of alcohol dependence or abuse because case findings have been based on screening questionnaires instead of using in-depth diagnostic criteria and detection rates have been assessed by analyzing patient records instead of directly interviewing the physician. To test this hypothesis, consecutive patients of a general hospital (N=436) and of 12 randomly selected general practices (N=929) were examined. A two-step diagnostic procedure included screening questionnaires and a diagnostic interview (SCAN). The analysis compares detection rates based on methods used in previous studies to data using more precise methods. Physicians' detection rates ranged from 37.0% to 88.9% in the general hospital and from 11.1% to 74.7% in general practices depending on methods used. The physicians' detection rates could be improved by 10% (general hospital) and 20% (general practice) through the additional use of a screening questionnaire. Of those patients assessed by the physicians as problem drinkers in the general hospital, 13.9% were referred to an addiction consultation-liaison service. Data reveal that physicians' abilities to detect problem drinkers have been underestimated. Routine screening procedures could play a major role in improving detection rates and reminding the physician to intervene.