In an age-matched sample of male and female inpatient alcoholics of the same ethnic background, the mean Michigan Alcoholism Screening Test (MAST) score declined significantly with age group and was lowest in elderly people. Females and first-admission subjects recorded lower mean MAST scores. A correlation was noted in both sexes between reported alcohol consumption and MAST scores. Although screening tests such as MAST have been found of value in detecting alcoholism in high-risk populations, this study of some of the MAST parameters in a clinical population suggests that some of the "invisible" and older alcoholics might not be grossly disturbed persons and that other more subtle behavioural clues to diagnosis should be determined. Despite the limitations inherent in any diagnostic technique, the ultimate detection of invisible alcoholics lies at the interface of clinical judgement, the use of screening tests, community awareness and the development of personal responsibility.