▪ Abstract  This chapter reviews research on the determinants and consequences of race and sex composition of organizations. Determinants include the composition of the qualified labor supply; employers' preferences, including the qualifications they require; the response of majority groups; and an establishment's attractiveness, size, and recruiting methods. The race and sex composition of an establishment affects workers' cross-group contact; stress, satisfaction, and turnover; cohesion; stereotyping; and evaluation. Composition also affects organizations themselves, including their performance, hiring and promotion practices, levels of job segregation, and wages and benefits. Theory-driven research is needed (a) on the causal mechanisms that underlie the relationships between organizational composition and its determinants and consequences and (b) on the form of the relationships between organizational composition and workers outcomes (e.g., cross-group contact, cohesion, turnover, etc). Research is needed on race and ethnic composition, with a special focus on the joint effects of race and sex.