Special attention must be given to obesity as it occurs in and affects ethnic minorities (that is, black Americans, Hispanic Americans, Asian and Pacific Islander Americans, American Indians and Alaska Natives, and Native Hawaiians) in the United States. In most of these groups, the prevalence of obesity is substantially higher than in whites, especially among women. Poverty and lower educational attainment, which are associated with higher than average rates of female obesity (independent of ethnicity), affect proportionately more persons in these minority populations than in white populations. Diabetes mellitus and certain other obesity-related conditions occur to a markedly greater than average extent in many minority populations. A high-risk body fat distribution (upper body or central obesity) occurs to a greater extent in some minority populations than in whites. Because of situational and cultural factors, effective obesity prevention and treatment approaches may need to be defined on an ethnicity-specific basis. Increased attention to obesity as it occurs in and affects diverse ethnic groups can help to address critical minority health issues. Such efforts can also broaden and enrich aspects of obesity research for which models based on white populations are inappropriate or limited.