Eighteen patients with congenitally corrected transposition of the great arteries had open heart repair for intracardiac associated defects. Fourteen patients (78%) are alive during the follow-up period (mean 4.5 years). Seventeen (94%) of the 18 patients had ventricular septal defect closure, and 12 (66%) insertion of a pulmonary artery conduit. Surgical repair of the tricuspid valve was required in 6 patients (33%) during the first operation and in 3 additional patients during a second operation (total 50%). When hemodynamic overload or cardiac compromise was detected after surgery it was directly related to identifiable residual defects such as atrioventricular valvular insufficiency, residual ventricular septal defect, or pulmonary conduit stenosis. Repeat open heart operation for residual defects was common during the follow-up period (8 of 18 patients, 44%). No patient showed primary systemic or pulmonary ventricular dysfunction during the follow-up period. None of the last 11 patients developed complete heart block. Postoperative intraventricular conduction defects were common and are presumably caused by surgical injury of the bundle branches. Our observations suggest that surgical repair of congenitally corrected transposition of the great arteries can be currently achieved with acceptable risk. Improved knowledge of the precise location of the specialized conduction system resulted in a marked decrease in the incidence of atrioventricular (A-V) block in patients with congenitally corrected transposition of the great arteries undergoing intracardiac repair. In the absence of postoperative residual defects it can be expected that longevity and quality of life will improve considerably, but many of these patients may require a repeat operation.