This study provides a preliminary examination of the efficacy of the Reflected Best Self Exercise. We conducted a field quasi-experiment with 108 adolescent leaders assigned to a 2 2 design: (1) valence of feedback (i.e., strengths-only versus strengths and improvement-oriented) and (2) source of feedback (i.e., professional (e.g., teachers, coaches, bosses) only versus professional and personal (e.g., friends and family)). By ANOVA, support was found for the hypothesis that feedback from the combination of professional and personal sources is associated with more positive emotional, agentic, and relational resources than feedback from only professional sources. Little support was found for the hypothesis that strengths-based feedback generates more positive emotional, agentic, or relational resources. Limitations, implications for practice and directions for future research are discussed.