Fifty chronic alcoholics (37 men and 13 women, ages 26--55, mean age 39.9 years) with different clinical syndromes (alcoholic psychosis, alcoholic encephalopathies) were studied by computerized cranial tomography. Cerebral atrophy was detected in 96% of all cases. Combined cortical and subcortical signs were encountered in almost all cases. Cortical atrophy seemed to be detectable more easily by CT than by pneumencephalography. The computerized tomographic findings were studied in their relations to age, sex, duration of abuse, clinical syndromes, frequency of relapse (and seizures, too), etc. Cerebral atrophy was correlated primarily with the subjects' age and the duration, and less with the intensity of alcoholism. The most distinct changes were found in delirium syndromes and, in cases with relapse of psychosis, especially in combination with seizures. Wernicke-Korsakow encephalopathies showed the widest third ventricles when combined with repeated syndromes of withdrawal in their case histories. Computerized tomographic examinations of ten patients during acute psychosis as well as 4 weeks later showed identical findings; transitory changes, e.g., cerebral edema, were not detected. Computerized cranial tomography appears to be extremely useful to study the numerous open questions concerning the pathogenetic role of age, duration, and severity of abuse with cerebral atrophy.