OBJECTIVE To investigate social and economic effects of obesity for black and white females, and to explore possible explanations for race differences in obesity effects. METHODS 1354 non-Hispanic black and 3097 non-Hispanic, non-black, women aged 25-33y in 1990 from the National Longitudinal Survey of Youth 1979-1990. METHODS Body mass index (BMI) evaluated at age 17-24y (1982) and 25-33y (1990). METHODS Logistic and linear regression of six labour market and marriage outcomes on early or attained BMI. Detailed controls for family socioeconomic background. RESULTS Socioeconomic effects of obesity appear larger for whites than blacks. Obesity is associated with low self-esteem among whites, but not blacks. Differences in self-esteem do not account for race differences in the effects of obesity on socioeconomic status. Lower probability of marriage and lower earnings of husbands among those who marry account for the majority of the income differences between obese white women and those of recommended weight. Occupational differences account for more than one fifth of the effect of obesity on the hourly wages of both white and black women. CONCLUSIONS Cultural differences may protect black women from the self-esteem loss associated with obesity for whites. However, differences in self-esteem do not account for the effects of obesity on socioeconomic status. Because the effect of obesity on the economic status of white women works primarily through marriage, it may therefore be less amenable to policy intervention to improve the labor market prospects of obese women.