The outcome of the Fontan-type operation for complex heart disease has been significantly improved, and low morbidity and mortality rates are reported. However, some problems still occur in late follow-up, including ventricular failure, hepatic congestion, supraventricular arrhythmia, cerebrovascular events, exercise intolerance, and residual or new cardiac lesions. Reinterventions after the Fontan-type operation for complex cardiac defects in 43 patients are reviewed. In addition to catheter interventions, the main reasons for reoperation were subaortic stenosis, pulmonary artery and vein obstructions, and interatrial shunt. Early intervention, particularly for subaortic obstruction, is recommended, and the Damus-Kay--Stansel anastomosis appears to be the procedure of choice. Reoperation was required in 6 of the 43 patients, with one operative death. The total event-free survival rate after 10 years of follow-up was 53%. The need for reoperation appears to be reduced after performing the total cavopulmonary shunt procedure compared to that after atriopulmonary connection. However, late arrhythmia remains a significant problem in this group of patients, and further assessment of the results of reintervention for arrhythmia is required.