Olfactory functioning was evaluated in 37 male detoxified alcoholics and in 21 age-matched nonalcoholic controls using the University of Pennsylvania Smell Identification Test (UPSIT). Of the original subjects, 23 alcoholics and 14 controls returned for reevaluation 3-4 months following initial testing. The results showed that alcoholics had significantly lower UPSIT scores than did the controls, both at baseline and follow-up testing. Thirty-two percent of the alcoholics' UPSIT scores, in comparison to five percent of the controls' scores, fell into the clinically impaired range. Although current smoking patterns correlated significantly with UPSIT indices, comparisons limited to nonsmokers still indicated that the alcoholics were significantly impaired on this olfactory task. Correlational analyses indicated that olfactory performance was unrelated to alcoholics' scores on visuoconceptual and language tasks. Correlations with MR-derived indices of CSF volume showed a highly significant relationship between UPSIT scores and cortical sulcal volumes. Additionally, alcoholics (N = 15) who remained abstinent had significantly higher scores at follow-up than those who were not abstinent (N = 8). These findings demonstrate that alcoholism is associated with basic olfactory impairments which are only partially reversible with abstinence and that cortical structures play an important role in this sensory loss.