Two studies assess pubertal timing and peer reputation as predictors of depression, self-worth, and anxiety among an urban, ethnically diverse sample of over 1,000 adolescent girls. Data were collected each fall and spring across the 3 middle school years, resulting in a 6 wave longitudinal design spanning 6^th through 8^th grade. The first study examines methodological challenges pertaining to the measurement of pubertal timing, as well as their implications for the link between early maturation and internalizing symptoms. A series of multilevel models revealed that participants who reported more advanced pubertal development compared to other girls in their grade were at risk for emotional distress; however, this risk was most pronounced when pubertal timing was measured at the first wave (fall of 6 ^th grade) When pubertal timing was assessed toward the end of middle school, it was unrelated to self-worth and less advanced development was then associated with anxiety. Results indicated that pubertal timing fluctuated within individuals from wave to wave and that these fluctuations were related to changes in emotional distress. Given that peer contextual factors appear to play a part in linking pubertal timing and adjustment, the second study aimed to assess peer reputation as a possible contextual factor contributing to this process. Hierarchical multiple regression analyses revealed that more advanced development at the start of middle school—when earlier maturation was found to be most "risky"—was associated with peer- and teacher-reported popularity, as well as a stronger reputation among peers as the target of rumors and gossip. Although seemingly paradoxical, reputations of popularity and peer harassment were in fact entwined; Social prominence appeared to put earlier developing girls at risk for reputational threats such as rumors. Having a reputation as popular among boys, in particular, was a social liability for earlier maturing girls. Finally, rumors and gossip targeting more advanced maturing girls helped account for some of their subsequent emotional distress. Knowledge of the peer mechanisms that might put earlier developing girls at risk for psychosocial maladjustment has implications for the design of prevention and intervention efforts aimed at improving adolescent well-being.