OBJECTIVE: We previously developed an 8-item self-assessment tool to identify individuals with a high probability of having albuminuria. This tool was developed and externally validated among non-Hispanic Whites and non-Hispanic Blacks. We sought to validate it in a multi-ethnic cohort that also included Hispanics and Chinese Americans. DESIGN: This is a cross-sectional study. SETTING: Data were collected using standardized questionnaires and spot urine samples at a baseline examination in 2000-2002. The 8 items in the self-assessment tool include age, race, gender, current cigarette smoking, history of diabetes, hypertension, or stroke, and self-rated health. PARTICIPANTS: Of 6,814 community-dwelling adults aged 45-84 years participating in the Multi-Ethnic Study of Atherosclerosis (MESA), 6,542 were included in the primary analysis. MAIN OUTCOME MEASURES: Albuminuria was defined as urine albumin-to-creatinine ratio ≥ 30 mg/g at baseline. RESULTS: Among non-Hispanic Whites, non-Hispanic Blacks, Hispanics, and Chinese Americans, the prevalence of albuminuria was 6.0%, 11.3%, 11.6%, and 10.8%, respectively. The c-statistic for discriminating participants with and without albuminuria was .731 (95% CI: .692, .771), .728 (95% CI: .687, .761), .747 (95% CI: .709, .784), and .761 (95% CI: .699, .814) for non-Hispanic Whites, non-Hispanic Blacks, Hispanics, and Chinese Americans, respectively. The self-assessment tool over-estimated the probability of albuminuria for non-Hispanic Whites and Blacks, but was well-calibrated for Hispanics and Chinese Americans. CONCLUSIONS: The albuminuria self-assessment tool maintained good test characteristics in this large multi-ethnic cohort, suggesting it may be helpful for increasing awareness of albuminuria in an ethnically diverse population.