Current views concerning the brain damage occasioned by alcohol abuse are reviewed. Diffuse cerebral changes appear to be common and partially reversible with prolonged abstinence. The possible determinants of such changes, and their relevance to functional deficits are discussed, with illustrations from work currently proceeding at the Institute of Psychiatry. Possible interactions between cortical and subcortical pathologies in contributing to the cognitive deficits shown by alcoholic patients are emphasised.