Evidence has supported the effectiveness of educational and psychosocial interventions that include strengths and promote the competence enhancement of schoolchildren. Nevertheless, students in low-income, culturally diverse urban schools who are academically underachieving may be the least likely but most in need to experience feedback about their strengths and potential competence for academic and career development. In the context of providing a preventative career exploration intervention, this instrumental case study of eight low-income Hispanic and Black urban middle school students identified as academically underachieving explored how four theoretically based types of success-learning experiences were associated with their evolving career-related interests and ability beliefs. Results include analyses of qualitative and quantitative data, themes (including those not captured by theoretical constructs), and narrative summaries of the accomplishment stories of these youth, as derived from interviews. Implications for theory, research, and practice are discussed. (Contains 1 table.)