Although the association between self-esteem and peer stress among adolescents is not unidirectional, and the two constructs probably coevolve and coexist over time, these two constructs and their possible mutual influence have rarely been tested in one single study. The present study examined whether there are bidirectional interactions between self-esteem and perceptions of peer stress across five or six annual waves using a nationally representative sample of two cohorts of South Korean youth. The sample comprised 2844 fourth graders (M = 9.86 years) and 3449 eighth graders (M = 13.79 years) at wave 1. Findings suggested that self-esteem was positively associated with peer stress in early and middle adolescence, whereas peer stress was negatively associated with self-esteem in early adolescence, but had positive links in middle and late adolescence. The implications of the results were discussed.