BACKGROUND The Maze procedure in patients without mitral valve disease remains controversial, because of the increased invasiveness and operation time required to create additional incisions in the atria. The aim of this study was to assess prognosis following the Maze procedure in patients without mitral valve disease. RESULTS One hundred and seven consecutive patients who underwent the Maze procedure between 2002 and 2008 was enrolled in this study. Patients were divided into two groups based on the presence or absence of mitral valve disease. Freedom from atrial fibrillation was compared by multivariate logistic regression analysis at discharge. The Kaplan-Meier method and Cox-proportional hazard analysis adjusted for other predictors were estimated to compare freedom from atrial fibrillation at follow-up. Follow-up was 98% complete and mean duration of follow-up was 457 days. Operation and aorta cross-clamp times were similar between groups. No differences were identified in freedom from atrial fibrillation at discharge (non-mitral valve surgery, 55% vs. mitral valve surgery, 66%) or follow-up (57% vs. 61%, respectively). In multivariate Cox proportional hazard modelling, the presence of mitral valve disease was not associated with a poor success rate of conversion. CONCLUSIONS Results of the Maze procedure for atrial fibrillation without mitral valve disease were acceptable. The Maze procedure could be a beneficial option for these patients to avoid adverse events of atrial fibrillation.