Objective: This study aims to determine the frequency of rhythm and conduction disorders in patients with tetralogy of Fallot and who underwent complete correction operation and the factors which may be related to them. Material and Methods: The study group, which operated with the diagnosis of tetralogy of Fallot, were taken 17 girls and 12 boys whose between ages of 4-20 years; and the control group 13 girls and 20 boys whose between ages 5,5-20 years. Enrolled 29 patients and 33 healthy children were performed electrocardiography (ECG), 24-hour Holter monitoring, echocardiography and exercise testing. Data were expressed in points, mean±SD and percent. Comparison of data were used with Chi-square test, Fisher's exact test and McNemar's test. Ethics committee approval was obtained for the study (2006/188). Results: In patient groups; 1) ECG records, complete right bundle block at the rate of 79.3%, 3.4% ventricular premature contraction (VPC) and 6.9% left anterior hemiblock and long QT were found to accompany right bundle block, 2) Holter records, rhythm disturbance was found 62% cases, 3) Exercise test frequent ventricular rhythm disturbance was established in 6,8% patients. In control groups; 1) ECG records, incomplete right bundle block was found at the rate of 6.1%, 2) Holter records rhythm disturbance was found 52% cases while no such disturbance was observed on exercise test. After operation, pulmonary failure was found at the rate of 58.6%, pulmonary stenosis 58.6% and ventricular septum defect 20.7%. Pulmonary failue was also present in all cases with pulmonary stenosis. No relation was found between the duration of follow up, the age and type of operation and rhythm disturbance. A positive relation was found between residual pulmonary stenosis and rhythm disturbance. It was also seen that the coexistence of pulmonary failure with pulmonary stenosis increased the rate of the establishment of rhythm disturbances. Conclusion: It was concluded that Holter monitorisation detected rhythm disturbances a higher rate than ECG. Therefore, it is beneficial to use Holter monitorisation and exercise test in addition to ECG. Copyright © 2014 by Türkiye Klinikleri.