Prior research links need for approval (NFA; the extent to which self-worth is contingent on peer approval or disapproval) to critical developmental outcomes, but little is known about how NFA develops over time or within social contexts. To address this gap, the present study used a sophisticated analytic approach (autoregressive latent trajectory modeling with standardized residuals) to examine dynamic associations between one salient social experience--peer victimization--and two dimensions of NFA, conceptualized in terms of approach motivation (NFA[subscript approach]; enhanced self-worth based on peer approval) and avoidance motivation (NFA[subscript avoid]; depleted self-worth based on peer disapproval). Following 636 youth (338 girls; M[subscript age] = 7.96 years at Wave 1; 66.7% White; 35.0% subsidized school lunch) from second to seventh grade, analyses revealed that peer victimization predicts subsequent increases in NFA[subscript avoid], which in turn predicts subsequent increases in victimization. Findings also revealed that although mean levels of NFA[subscript avoid] decrease during childhood, increases or decreases in NFA become more entrenched. Thus, childhood peer victimization may disrupt normative decreases in NFA[subscript avoid] and contribute to a cycle in which negative peer judgments increasingly foster low self-worth and further peer difficulties. Preventing this cycle may require encouraging peer-victimized youth to base their self-worth on internal standards rather than peer feedback while helping them develop positive relationships that promote self-worth.