Several studies have found that, all else equal, heavier women earn less. Previous research has been unable to determine whether high weight is the cause of low wages, the result of low wages, or whether unobserved factors cause both higher weight and lower wages. Applying the method of instrumental variables to data from the National Longitudinal Survey of Youth, this paper attempts to generate consistent estimates of the effect of weight on labor market outcomes for women. Three labor market outcomes are studied: hourly wages, employment, and sector of occupation. This paper finds that weight lowers wages for white women; among this group, a difference in weight of two standard deviations (roughly sixty-five pounds) is associated with a difference in wages of 7%. In absolute value, this is equivalent to the wage effect of roughly one year of education, two years of job tenure, or three years of work experience. In contrast, this paper finds only weak evidence that weight lowers wages for hispanic women, and no evidence that weight lowers the wages of black women. This paper also concludes that there is no effect of weight on the probability of employment or sector of occupation.