Background. The prevalence of overweight among Black women in the US is higher than among White women, but the causes are unknown. Methods. We examined the weight change for 514 Black and 2,770 White women who entered the first Health and Nutrition Examination Survey (1971-75) at ages 25-44 years and were weighed again a decade later. We used multivariate analyses to estimate the weight-change effects associated with race, family income, education, and marital change. Results. The mean weight change was greater for the Black women than the White women. Adjustments for height, duration of follow-up, baseline body mass index, and multiple demographic, social, and behavioral variables did not reduce this mean Black-White difference. Conclusions. Among US women, Black race is independently associated with a reduced likelihood of major weight loss, but not with major weight gain. Women at greatest risk of weight gain are those with education below college level, those entering marriage, and those with very low family income.