Service-learning (SL) has become a popular teaching method everywhere from elementary schools to colleges. Despite the increased presence of SL in the education world, it is still unclear what student outcomes are associated with SL programs and what factors are related to more effective programs. A meta-analysis of 62 studies involving 11,837 students indicated that, compared to controls, students participating in SL programs demonstrated significant gains in five outcome areas: attitudes toward self, attitudes toward school and learning, civic engagement, social skills, and academic performance. Mean effects ranged from 0.27 to 0.43. Furthermore, as predicted, there was empirical support for the position that following certain recommended practices--such as linking to curriculum, voice, community involvement, and reflection--was associated with better outcomes. Current data should be gratifying for educators who incorporate SL into their courses, and should encourage more SL research to understand how students benefit and what conditions foster their growth and development. (Contains 3 tables and 5 footnotes.)