The objective of the present study was to determine the role of sex steroids in the development of self-perceived competence during adolescence. The Harter Self-Perception Scale was administered to 56 adolescents with delayed puberty who were receiving depo-testosterone (males) or conjugated estrogens (females) administered in 3-month blocks alternating with placebo. Treatment was given at three dose levels approximating early, middle, and late pubertal replacement levels. Hormone treatments had a significant positive effect for both males and females in one subscale domain — perceived job competence. Significant positive hormone effects were also obtained for perceptions of romantic appeal and close friendship in females and perception of athletic abilities in males. It can be inferred from the results of this study that the hormonal changes associated with sexual maturation have targeted influences on specific domains of self-perceived competence and that there are clear gender differences.