Results from a random sample survey of US Air Force personnel show that 4.6 per cent exhibit alcohol dependence, indicated by symptoms of withdrawal and impaired control over drinking. An additional 9.3 per cent can be identified as nondependent alcohol abusers, indicated by serious adverse effects of drinking (such as arrest, accident, hospitalization, or significant work impairment) or by heavy alcohol consumption (over 150 ml of ethanol daily). Compared with data from supervisors and official records, survey results did not understate alcohol-related problems. Survey reports of alcohol consumption did underestimate alcoholic beverage sales by about 20 per cent, but adjustments for this discrepancy increased the prevalence rate by less than one percentage point. Rates of serious alcohol abuse among representative samples of males in the U.S. Army, Navy, Air Force, and civilian populations were also compared. Although the rates were higher in the military than among civilians, most of the difference was associated with the higher-risk demographic characteristics of military personnel, who are more likely than civilians to be young unmarried males. Results indicate that the rate of alcohol abuse in the military is about the same as in civilian groups with comparable demographic characteristics.