We evaluated the usefulness of the maze procedure among patients with atrial fibrillation undergoing mitral valve surgery. Seven matched-controlled and four randomized trials were identified from Medline English language papers (1995 to 2005). After 2 to 8 years of follow-up in matched-controlled studies, odds ratio and 95% confidence interval (CI) for atrial fibrillation free, embolic events free, and long-term survival for those treated with maze were 12.51 (95% CI: 9.18 to 17.03), 9.35 (95% CI: 5.11 to 17.13), and 2.27 (95% CI: 1.21 to 4.27), respectively. Correspondingly, after 1 to 1.5 years of follow-up in randomized trials, they were 9.01 (95% CI: 4.21 to 19.3), 5.19 (95% CI: 0.50 to 53.6), and 0.49 (95% CI: 0.12 to 1.93), respectively. The addition of the maze procedure to mitral valve surgery was more likely to maintain patients in sinus rhythm and may lower embolic events, including stroke, but did not necessarily improve long-term survival.