Introduction. In the group of adult patients with arrhythmias and congenital heart defects, the problems of choosing the volume of arrhythmia elimination, indications for simultaneous or staged correction, evaluation of the early and long-term outcomes after correction of the defect for the detection and treatment of arrhythmia are relevant. Objective: to evaluate the long-term outcomes of congenital heart defects and concomitant arrhythmias surgical treatment in adult patients. Material and methods. The subjects (n = 378) were divided into groups: 1st (n = 217) – who had no history of arrhythmias; 2nd (n = 89) – with arrhythmias and underwent isolated correction of the defect (without antiarrhythmic aid); 3rd (n = 52) – with arrhythmias and underwent a simultaneous correction of the defect procedure "Labyrinth"; 4th (n = 20) – with arrhythmias and who underwent an antiarrhythmic procedure before correction of the defect. The primary control points were: long-term survival and freedom from arrhythmias in the long term; secondary: the frequency of permanent pacemaker implantations and repeated antiarrhythmic procedures, acute disorders of cerebral circulation after surgery, the number of repeated visits with arrhythmias, chronic heart failure II–III functional class according to NYHA in the long-term follow-up. The methods of assessing the long-term period were an in-person examination or a telephone survey with obtaining medical documentation through social networks. Results. The age in the groups was 52.5 ± 7.4 years for 1st group, 55 ± 9.8 years for 2nd group, 53.2±8.5 years for 3rd group and 55.6±9.4 years for 4th group. Hospital mortality was: 4 (1.8%) – in 1st group, 4 (4.5%) – in 2nd, 2 (3.8%) – in 3rd and 0 for 4th group (p2–4= 0.02). 10-year survival was higher in 4th group (100%) and 3rd group (96.5 ± 9.1%) compared to groups 1st (87.5 ± 1.9%) and 2nd (90 ± 5%) respectively. 5-year freedom from arrhythmias did not differ in 3rd and 4th groups (94.67 ± 3.74% and 90.0 ± 9.48% respectively, p = 0.296), significantly exceeding groups 1st (65.80 ± 3.47%) and 2nd (28.14 ± 5.50%). The highest 10-year freedom from arrhythmias was found in 3rd group – 77.43 ± 8.50% versus 48.36 ± 4.55% (p = 0.01) in 1st group, 11.79 ± 5.93% (p = 0.0001) in 2nd group and 48.0 ± 22.9% (p = 0.02) in 4th group respectively. Conclusions. Patients without a history of arrhythmias are at risk of their development in the long-term period after correction of the defect (10-year freedom from heart rhythm disorders – 48.36 ± 4.55%). The simultaneous procedure Maze with surgical correction, as well as performing catheter ablation until the defect is eliminated, significantly improve the indicators of cumulative 5 and 10-year survival and freedom from arrhythmias.