Researchers have shown the benefits of mentoring in both personal and professional growth. It would seem that group mentoring would only enhance those benefits. This work represents a literature review of peer-reviewed articles and dissertations that contribute to the theory and research of group mentoring. This work reviews the articles that contributed to the development of group mentoring theory as well as relevant research. Four primary types of group mentoring emerge--peer group, one-to-many, many-to-one, and many-to-many. Despite over 20 years of research, significant gaps remain in the research methods, demographic focus, and fields of study. The review concludes with recommendations for future research. (Contains 1 table.)