This study examines bi-directional links between social anxiety and multiple aspects of peer relations (peer acceptance, peer victimization, and relationship quality) in a longitudinal sample of 1528 adolescents assessed twice with one year between (754 females and 774 males; M = 14.7 years of age). Lower levels of peer acceptance predicted increases in social anxiety. Social anxiety predicted decreases in relationship support for males and increases in peer victimization for females. Collectively our findings suggest that peers seem to play a significant role for adolescent mental health and social anxiety seems to interfere with healthy peer relations. Importantly, developmental pathways for social anxiety seem to differ for adolescent females and males. (Contains 2 tables and 1 figure.)