Aim This study aimed to review, consolidate and analyse the findings of studies investigating the efficacy of anal fistula plugs ( AFPs) in treating fistula-in-ano in patients with Crohn's disease. Method A literature review was conducted via Pubmed, Embase, Medline, Scopus and the Cochrane Library for the period 1995-2015. Articles were selected and reviewed based on specific inclusion and exclusion criteria. Results A total of 16 studies were extracted, of which 12 were included in the systematic review. In total, 84 patients ( n = 1-20 per study) with a median age of 45 (18-72) years and a median follow-up time of 9 (3-24) months were analysed. The total success rate, defined as closure of the fistula tract, was 49/84 (58.3%, 95% CI 47-69). Success in patients with recurrent anal fistulae was 2/5 (40%, 95% CI 5-85). Overall, the success rates of Surgisis® and GORE® BIO-A® brand plugs were 48/80 (60%, 95% CI 48-71) and 1/4 (25%, 95% CI 1-81). The recurrence rate of fistula-in-ano in the five studies that reported recurrence was 3/22 (13.6%). In two comparative studies, inferior overall success rates were found in patients who received preoperative immunomodulators vs those who did not [3/11 (27.3%) vs 17/23 (73.9%)]. Conclusion The studies suggest that the use of an AFP in patients with Crohn's disease is a safe procedure with reasonable success, little morbidity and a low risk of incontinence. The current literature is limited by a number of factors, including small study cohorts, grouping of fistulae in Crohn's disease with other types of anal fistula, short and highly variable follow-up times and multiple confounding factors such as number of fistula tracts, use of preoperative steroids or immunosuppressants, previous use of setons and variation in surgical technique. [ABSTRACT FROM AUTHOR]