Background/Context: A review of the literature demonstrates that grade retention often fails to improve the academic and socioemotional outcomes of retained students. Although little empirical work on peer tutoring has focused specifically on retained students, the literature suggests that those students who act as peer tutors often experience improved school performance and self-concepts. Purpose of Study: This work developed out of a concern that elementary school students being held back to repeat a grade, or retained, were not benefiting academically from nonpromotion. The purpose of this action research study was to identify and implement an intervention that would improve the academic and socioemotional outcomes of a twice-retained third-grade student. Setting: This study took place in a New York City public elementary school. Intervention: The intervention involved implementing a 12-week peer tutoring program in which a retained third-grade student tutored a struggling classmate in mathematics. Research Design: This is an action research study in which the author conducted research and implemented an intervention in her own classroom. Results: After serving as a peer tutor, this student experienced increased math achievement, an improved self-concept, and better classroom behavior. These results suggest that having struggling students serve as peer tutors may be effective in improving both their academic achievement and socioemotional outcomes.