The Sexual Self-Concept Inventory (SSCI) was developed to assess sexual self-concept in an ethnically diverse sample of urban early adolescent girls. Three scales (Sexual Arousability, Sexual Agency, and Negative Sexual Affect) were shown to be distinct and reliable dimensions of girls' sexual self-concepts. Validity was established through comparisons with established instruments. Sexual Arousability and Sexual Agency were associated with positive sexual self- esteem, positive future orientation toward sex, intentions to engage in intercourse, and lower levels of sexual experience. Negative Sexual Affect was associated with stronger abstinence attitudes and lack of intentions or orientation toward sex in the near future. The results indicate that the SSCI constitutes a valid means of assessing early adolescent girls' views of their sexuality and sexual behavior and may be of use in studies of health and risk-related decision making.