The Sexual Competence and Interaction Competence in Youth is a self-report questionnaire that aims to measure sexual competence and interaction competence in adolescents. The study sample consisted of 276 female undergraduate students (M = 20.95 years, SD = 2.00 years). The factor structure of the questionnaire was calculated on full sample data. A subsample was used to calculate the validity and internal consistency (N = 236; M = 20.88 years, SD = 1.96). The test-retest reliability was also calculated in a subsample (N = 82; M = 21.45 years, SD = 1.74 years). On the basis of an exploratory factor analysis, 8 factors were extracted: (a) communication about sex, (b) refusing sex, (c) positive sexual attitudes, (d) male role in sexual interaction, (e) contraceptive use, (f) not suppressing problems and desires regarding sex, (g) sexual assertiveness, and (h) sexual hedonism. The subscales possess adequate internal consistency and moderate to excellent test-retest reliability. A higher order principal component analysis revealed a 2-factor structure that appears to adequately represent the sexual competence and interaction competence constructs. Furthermore, convergent and discriminant validity were considered to be good. The results indicate that the Sexual Competence and Interaction Competence in Youth may be a useful instrument to measure sexual and interaction competence among adolescents.