The long-term effect of concomitant surgical ablation (SA) on clinical outcomes in an unselected population of patients has not been sufficiently reported in randomized studies. The aim of this study was to assess clinical outcomes of the SA after 5 years of follow-up. The PRAGUE-12 study was a prospective, randomized clinical trial assessing cardiac surgery with ablation for AF vs cardiac surgery alone. Patients with AF who were also indicated for cardiac surgery (coronary artery disease [CAD], valve surgery) were randomized to SA or control (no ablation) group. All patients were followed for 5 years. The primary endpoint was a composite of cardiovascular death, stroke, hospitalization for heart failure, or severe bleeding. Secondary endpoint was a recurrence of AF. A total of 207 patients were analyzed (SA group = 108 patients, control group = 99 patients). Both groups were similar relative to important clinical characteristics except for CAD, which was more common in the control group. Cumulative incidence curves showed a higher incidence of the primary endpoint in the control group (P = .024, Gray's test). However, after adjusting for all covariables, the difference between groups was not significant (subhazard ratio [SHR] 0.69 [0.47-1.02], P = .068). The incidence of stroke and AF recurrences were significantly reduced in the SA group, and remained significant even after adjustment for all covariables, including CAD (stroke: SHR 0.32 [0.12-0.84], P = .02, AF recurrences: SHR 0.44 [0.31-0.62], P < .001). Concomitant SA of AF is associated with a greater likelihood of maintaining sinus rhythm and a decreased risk of stroke.