SummaryResults of recent investigations suggest that Alzheimer disease (AD) has a more deleterious effect on language in women than in men. This intriguing finding motivated an analysis of the language performance of probable AD patients, equally divided as to gender, on a variety of language comprehension and production tests. Cross-sectional data were available for 63 probable AD subjects and longitudinal data were available for 26. In addition to analysis of covariance used with the cross-sectional data, effect sizes were calculated. The longitudinal data were analyzed with repeated-measures analyses of covariance. The sum of scores on the orientation items of the Mini-Mental State Examination was used as the covariate in both analyses. No significant differences between the performance scores of male and female subjects were obtained for either the cross-sectional or longitudinal data. All effect sizes of gender were relatively small, with female patients outperforming males on most language tests. Results are discussed in the context of previous findings and comparison of the effect sizes among studies