A neighborhood's normative climate is linked to, but conceptually distinct from, its structural characteristics such as poverty and racial/ethnic composition. Given the deleterious consequences of early sexual activity for adolescent health and well-being, it is important to assess normative influences on youth behaviors such as sexual debut, number of sex partners, and involvement in casual sexual experiences. The current study moves beyond prior research by constructing a measure of normative climate that more fully captures neighborhood norms, and analyzing the influence of normative climate on behavior in a longitudinal framework. Using recently geo-coded data from the Toledo Adolescent Relationships Study (TARS), we analyze the effect of normative climate on adolescents' sexual behaviors. Results indicate that variation in neighborhood normative climates increases adolescents' odds of sexual debut and casual sex, and is associated with their number of sex partners, even after accounting for neighborhood structural disadvantage and demographic risk factors.