Ten patients with complete atrioventricular (AV) canal and tetralogy of Fallot or double-outlet right ventricle (DORV) with subaortic ventricular septal defect and pulmonary stenosis underwent complete repair. Associated cardiac anomalies were frequent, and 3 patients had situs ambiguus and 1 had situs inversus. Two (40%) of the 5 patients with comple AV canal and tetralogy of Fallot died in hospital, as did 3 (60%) of the 5 with complete AV canal and DORV. No deaths occurred among the 4 patients in whom repair could be done without using a transannular patch across the pulmonary valve ring or a valved external conduit. Five (62%) of the 8 without major associated malformations survived. Preoperative study must define completely the malformation. The repair, done through the right atrium alone or in combination with a right ventriculotomy, is most easily accomplished with separate patches for the ventricular and atrial components of the septal defect.