A transactional, interpersonal framework involving adolescents' reassurance-seeking and peer experiences may be useful for understanding the emergence of gender differences in depression prevalence during the adolescent transition. Sociometric nominations of peer acceptance/rejection and ratings of friendship quality provided by adolescents and their friends were used to measure peer experiences among 6th-8th-grade adolescents (N=520) over 3 annual time points. After controlling for age and pubertal development, significant but small prospective effects offered mixed support for hypotheses: (a) depressive symptoms and negative peer relations predicted increasing levels of girls' reassurance-seeking; (b) initial levels of reassurance-seeking and depressive symptoms predicted deteriorating friendship quality among girls and low friendship stability, respectively; and (c) reassurance-seeking combined with poor peer experiences predicted increases in girls' depressive symptoms.