Structured extracurricular activity participation has been linked to self-esteem and other indicators of positive youth development. This article describes the theoretical basis for this relationship, centering on extracurricular activities as a location for identity development. A summary of the empirical evidence points to the importance of breadth of participation for self-esteem and related measures of psychological well-being. Consideration is also given to variations by gender, race/ethnicity, and social context. Although the literature points to the relevance of adolescent extracurricular involvement for self-esteem, further research is needed to understand the nuances of this relationship. Additionally, adults should exercise caution about forcing adolescents into activities. Instead, adults and communities should create environments that encourage youth to try new things and provide access to a variety of activities. Within extracurricular activities, there should be support for the factors conducive to building self-esteem and other aspects of positive youth development.