Little information exists regarding the performance of Spanish-speaking versus English-speaking patients with Alzheimer's disease (AD) on the Mini-Mental State Examination and the Mattis Dementia Rating Scale. In an attempt to identify culturally biased MMSE items or DRS subscales, we matched Spanish-speaking Hispanic and English-speaking non-Hispanic White community-dwelling AD patients by their MMSE scores and examined specific items within each scale. Our findings indicate that Hispanic AD patients perform significantly worse than non-Hispanics in terms of total DRS score, scores on the DRS subscales for Conceptualization and Memory, and on serial subtraction (or backward spelling item) of the MMSE. While mildly to moderately demented Hispanic and non-Hispanic patients obtained comparable scores on the DRS, severely impaired Spanish-speaking participants obtained considerably lower DRS scores than their English-speaking counterparts. The discrepancy in the DRS scores of the severely impaired Hispanic and non-Hispanic examinees might reflect a cultural bias in the test or educational differences between the groups. Alternatively, the DRS may be more sensitive than the MMSE for detecting severe cognitive impairment in Hispanic patients. (JINS, 1999, 5, 301–307.)