An improved method for the measurement of erythrocyte aldehyde dehydrogenase (ALDH) activity was developed and used to determine the enzyme activity in 38 male Caucasian patients admitted to this VA Medical Center for alcohol detoxification. Patients who had been treated within a year prior to the study with any drug known to inhibit ALDH, such as disulfiram, were excluded from the study. In agreement with previous reports, the erythrocyte ALDH levels were decreased relative to non-alcoholic controls. However, no useful correlation was found between the erythrocyte ALDH levels and any of 35 standard clinical chemical and hematological parameters including those that indicated alcoholic liver disease.