Given the preponderance of Gamblers Anonymous (GA), there has been relatively little effort to explore the existing evidence base on its effectiveness as a recovery approach for problem gambling. To remedy this gap in the literature we conducted a scoping review of the literature on mutual aid for individuals experiencing problem gambling published between 2002 and 2015. We searched 13 databases and reviewed reference lists and websites of relevant organizations. We reviewed records for eligibility and extracted relevant data from eligible articles. Three reviewers independently assessed the methodological quality of the included studies using the Mixed Methods Appraisal Tool. We identified 17 studies in 25 publications that were eligible for inclusion. Most studies were conducted in the United States, were cross-sectional in design, and involved both male and female adult participants. Results indicate that the evidence for the effectiveness of GA either as a control condition or in conjunction with formal treatment or medication is inconsistent. An emphasis on patience, using the Serenity Prayer as a way to gain acceptance of financial matters and reality, and absolute assertion of identity as a "compulsive gambler" were identified as important aspects of GA's recovery culture. There is a need for large-scale randomized controlled trials to determine GA's effectiveness, as well as research exploring the mechanisms through which GA works, barriers to GA as a recovery approach, and the status of women in the fellowship.