This review and critique examines cognitive developmental theory and research concerning the development of gender knowledge, and social learning theory and research concerning the development of sex-role stereotypes. A preliminary integrated model of the development of gender knowledge and sex-role stereotypes in young children is presented. Kohlberg's cognitive developmental view is a primarily qualitative theory of gender knowledge based on cognitive organizational changes. Research supporting this view indicates that, by age 3, children, given clear cues, can identify the sexes. The recognition that gender is a permanent attribute, however, takes several years to stabilize. Social learning theory quantitatively discusses the development of knowledge of sex-role stereotypes in terms of input from the social environment. Research indicates that the acquisition and expression of culturally stereotyped norms of sex-appropriate role behavior begin as early as age 3 and increase throughout the preschool period. Since the development of gender knowledge and sex-role stereotypes occurs concurrently in young children, it seems that the two theoretical and empirical approaches need to be combined. A preliminary integrated model and methodology is presented which is designed to emphasize the interaction between cognitive organizational changes and the environment's role in the learning process. (Author/MS)