One hundred six infants were seen at the University of California Medical Center between 1974 and 1981 with the diagnosis of truncus arteriosus. One hundred of these underwent physiologic correction prior to 6 months of age. Six infants died prior to operation while undergoing intense medical therapy to improve their basic condition. There were 11 operative deaths with a mortality rate of 11%. Of the 86 long-term survivors, 55 have returned for conduit change because of either body growth or pseudointima proliferation of the conduit. There had been no mortalities at the time of conduit change, and 29 of these were repaired using a straight tube between the ventricle and pulmonary trunk, while 26 had valve conduits placed. Physiologic correction in the first 6 months of life has been accomplished with a low mortality rate and apparent good long-term results with none of the survivors having evidence of elevated pulmonary vascular resistance.