We compared initial severity, amount of improvement, and rate of improvement of aphasia in African-Americans and Caucasians. Study patients were aphasic subsequent to a first, left hemisphere, thromboembolic infarct, and all were entered in a 44-week treatment trial designed to provide 6-8 h of treatment each week between 4 and 48 weeks post-onset. There was no significant difference between African-Americans and Caucasians in severity of aphasia on the Porch Index of Communicative Ability, a word fluency measure, or the Token Test prior to the initiation of treatment at 4 weeks post-onset. At 48 weeks post-onset, African-Americans performed significantly lower on the Porch Index of Communicative Ability Gestural and Graphic modality scores. Both African-American and Caucasian aphasic patients displayed significant improvement in aphasia during the 44-week treatment trial, and there were no significant differences between groups in the amount or rate of improvement. Thus, our samples of African-American and Caucasian aphasic patients displayed essentially the same initial severity, amount of improvement, and rate of improvement of aphasia during the first year post-onset.