We compared the extent to which subjective report of activities of daily living (ADLs) by caregivers and older adults were associated with objective measures of older adults’ cognition. In independent studies (Study 1 N = 238; Study 2 N = 295), bivariate correlations and multiple regression analyses examined the association of caregiver and self-rated reports of older adult basic, instrumental, and total ADLs and older adult cognition. We examined the magnitude of the caregiver/self-report discrepancy and older adult cognition. In both studies, caregiver reports more accurately accounted for older adult cognitive differences. Older adult visuospatial/constructional deficits were uniquely related to caregiver basic ADL reports. Results indicate that caregiver reports of older adult ADLs are more reliable indicators of older adult cognition than self-reports, and this difference grows as older adult cognition decreases. Thus, older adult ADL assessment may be useful in providing information on potential cognitive decline.