Thirteen patients underwent repair of atrioventricular septal defect [AVSD] from January 1980 to July 1989 at Kyungpook National University Hospital. Two patients had complete AVSD [Rastelli type A] and eleven patients had partial AVSD [ostium primum atrial septal defect and cleft of anterior mitral leaflet]. In all the patients of partial AVSD, atrial septal defect was closed with Dacron patch and the mitral cleft was approximated with interrupted simple sutures. In one patient of complete AVSD, one patch technique was used to close the atrial and ventricular septal defect, and in the other patient of complete AVSD, two patch technique was used. In six patients, there were associated anomalies; four had isolated ostium secundum ASD, two had patent foramen ovale. Postoperative complete A-V block was noted in a patient of partial AVSD, but it was returned to 1st degree A-V block 30 months later and in another case of partial AVSD, severe congestive heart failure [NYHA functional class IV] due to residual mitral insufficiency was developed postoperatively, but this patient was recovered to the state of functional class I after receiving mitral valve replacement. There was one hospital death [8 %] resulting from low cardiac output.