As the higher education landscape continues to diversify, intercultural effectiveness comes to the forefront among important outcomes for students. Service learning is one programmatic tool that institutions of higher education can use to foster the development of intercultural effectiveness. This study provides evidence that service learning is correlated to intercultural effectiveness, but also offers the caveat that implementation and facilitation of service learning to include good practices is crucial in its effectiveness. Utilizing data from the Wabash National Study of Liberal Arts Education (WNS), the current study is guided by the following questions: (1) What is the effect of service learning on undergraduate students' intercultural effectiveness?; and (2) Are mediating variables influencing the effects of service learning on undergraduate students' intercultural effectiveness? The study's sample (2006-2010 cohort) includes 17 four-year institutions--varying in institutional control, size, and selectivity--that participated in the WNS. Liberal arts colleges were purposefully oversampled within the WNS. Findings suggest that the effect of participation in service learning is mediated by academic challenge, integrative learning, diversity experiences, and positive interactions with diverse peers. Suggestions for implementation and practical application are included.