A measure of sex typing and androgyny in children was developed based on the Bem Sex Role Inventory (BSRI; Bem, 1974). The Children's Sex Role Inventory (CSRI) was correlated with the BSRI in an adult sample to establish the equivalence of the two inventories for use in developmental research spanning middle childhood and adulthood. Ss were 145 third, fourth, sixth, and seventh graders, 130 of whom were retested 1 year later. Reliability was established through high internal consistency of femininity and masculinity scales (average α = .81) and stable test-retest reliabilities averaging .60. Validity of the scales was evident in significant (p < .01) gender differences on both scales and in confirmation of hypothesized relations between gender-role categories and measures of (a) sex-typed toy and activity preferences; (b) self-perceptions of global self-worth, scholastic competence, social acceptance, athletic competence, physical attractiveness, and behavioral conduct; and (c) cognitive performance. A short form of the CSRI was also developed.