Background: Women and people of color are consistently underrepresented in science, technology, engineering, and math (STEM) fields and careers. Though there are myriad factors underlying these gaps, one potential variable may be the extent to which these students feel connected to their STEM classroom experiences. Purpose: The present study investigated the potential of a service-learning experience to support STEM engagement for underrepresented youth. Methodology/Approach: Two cohorts of high school students participated in a summer program through which they built "solar suitcases" to provide electricity for communities in need. Observations and student surveys measured student engagement and changes in STEM attitudes, dispositions, and beliefs. Findings/Conclusions: Students were highly engaged in service-learning activities and demonstrated improved Science Fascination, Science Values, and STEM Career Affinity after participating in the program. Implications: Implications for the design and delivery of culturally relevant service-learning experiences are discussed.