Introduction <p>There are limited studies evaluating the impact of concomitant tricuspid annuloplasty (TAP) on maze surgery outcomes in atrial fibrillation (AF) patients undergoing mitral valve (MV) surgery. This study aimed to assess the efficacy of the maze procedure in restoring sinus rhythm (SR) post-MV surgery, with and without concomitant TAP.</p> Methods <p>We reviewed 88 patients who underwent MV surgery with the maze procedure from January 2010 to December 2020. The primary endpoints included the 5-year postoperative SR restoration rate in patients undergoing bi-atrial maze (BM) versus left atrial maze (LM) procedures, with and without concomitant TAP, and the identification of risk factors for postoperative arrhythmia in the total cohort. Secondary outcomes included hospital mortality, postoperative heart failure, stroke, and pacemaker implantation.</p> Results <p>The 30-day mortality rate in the study population was 2.3%. There was no significant difference in SR restoration at hospital discharge between the BM and LM groups (BM, 76.2%; LM, 73.9%; <i>p</i>=0.80). In patients who did not undergo TAP, the 5-year SR restoration rates between the BM and LM groups were not significantly different (log-rank test: <i>p</i>=0.65). However, in those undergoing TAP, the BM group demonstrated a significantly higher 5-year SR restoration rate compared to the LM group (BM+TAP, 74.2% vs LM+TAP, 42.1%; log-rank test: <i>p</i>=0.044). Multivariate analysis identified TAP with the LM procedure (hazard ratio (HR), 2.94; 95% confidence interval (CI), 1.25–6.92; <i>p</i>=0.014) and long-standing persistent atrial fibrillation (AF) (HR, 3.35; 95% CI, 1.46–7.68; <i>p</i>=0.0044) as significant predictors of postoperative arrhythmia.</p> Conclusion <p>The BM procedure may be crucial in restoring postoperative SR, particularly in patients undergoing concomitant TAP during MV surgery.</p> Graphical Abstract <p></p>