We show that individuals in a job with a higher percentage of females earn lower starting wages with an employing organization. This holds true with controls for individuals’ human capital, job demands for skill or difficult working conditions, and detailed industry. We use a measure of sex composition that applies to detailed jobs: cells in a three-digit census occupation by three-digit census industry matrix. We use pooled panel data from the 1979–1987 waves of the National Longitudinal Survey of Youth. The unit of analysis is the spell—the time in which a person worked for one organization. The dependent variable is the first wage in the spell. We use models with fixed-effects to control for unmeasured, unchanging individual characteristics; we also show results from OLS and weighted models for comparison. The negative effect on wages of the percentage female in one’s job is robust across procedures for black women, white women, and white men. For black men the sign is always negative but the coefficient is often nonsignificant.