Objective. To evaluate long-term results of left atrial modification of Maze procedure in comparison with isolation of the pulmonary veins in the surgical treatment of paroxysmal atrial fibrillation (AF) concomitant to correction of mitral valve disease. Material and methods. Between February 2008 and May 2013, 112 patients with a mean age of 53.2 (standard deviation 7.5) years underwent mitral valve surgery and concomitant bipolar radiofrequency ablation for paroxysmal AF. Patients were randomized into two groups: pulmonary vein isolation (PVI, n=56) and left atrial Maze (LAM, n=56). After surgery, a loop recorder for continuous electrocardiographic monitoring was implanted. The rate, complications, quality of life (SF-36) were assessed before surgery and in the long term. The mean follow-up was 40.2 months (standard deviation 3.5 months), and the patients' data were evaluated every 6 months. Results. The incidence of the long-term AF paroxysm recurrence was significantly higher in the PVI group than in the LAM group (84.3 vs 57.9%, log-rank test, p=0.005). The Kaplan–Meier survival after 36 months was 92.9±3.4% and 91.1±3.8% in PVI and LAM groups, accordingly (log-rank test, p=0.73). The main predictors of AF late recurrence were deficient ablation lesion sets and increasing of baseline pulmonary artery pressure. Conclusion. The quality of life after LAM is significantly higher than after PVI, though statistically significant difference was achieved only for social functioning in the long term. Multivariate regression analysis showed that the presence of AF in the long term is a significant negative predictor affecting 4 from 8 main quality of life parameters.