As today's business world and society become more diverse, it is essential for colleges and universities to prepare students to work and live in that diverse world, and service-learning is one tool for that education. This study presents a critical review of 55 studies of the impact of service-learning participation on students' diversity outcomes, identifying six diversity-related outcomes that emerge from these studies. The paper also identifies five major limitations of the existing body of research, and offers suggestions for researchers to conduct and write about this research in ways that provide an empirical basis for effective service-learning practice. (Contains 2 tables.)