This cross-sectional analysis evaluated the association between ethnicity and cognitive performance and determined whether education modifies this association for nondemented older people (103 African Americans, 1,388 Japanese Americans, 2,306 Caucasians) in a study of dementia incidence. African Americans scored lower (median 89 out of 100) than Japanese Americans (93) and Caucasians (94) on the Cognitive Abilities Screening Instrument (CASI). Education affected CASI scores differently. The gap decreased between African Americans in high education groups compared with Japanese Americans and Caucasians. Adjustment for gender, depression, and comorbidities did not change this association. The increased ethnic discrepancy in cognitive test scores in low education groups may reflect differential educational quality.