Twenty-seven consecutive patients less than 2 years of age underwent primary intracardiac repair of complete atrioventricular (A-V) canal. Three (19 percent) of the 16 operated on after January 1, 1975 died in the hospital, a smaller proportion than the 8 of 11 patients who died in the hospital after operation between 1972 and 1975 ( P = 0.005). The date of operation as a continuous variable is also related to the probability of hospital death ( P = 0.016). Age at operation was not related to hospital mortality among the total group of 27 infants, nor were the anatomic characteristics of the anterior and posterior bridging leaflets, the location and size of the interventricular communications or the duration or technique of profound hypothermia (total circulatory arrest versus low perfusion flow rate). The improved results in the 16 patients operated on since January 1, 1975 are believed to be primarily the result of an improved ability to construct “mitral” and “tricuspid” valves from the common A-V valve. Fourteen of the 16 hospital survivors are alive and well 5 to 60 months after operation. These results and the natural history of patients with this malformation indicate that there should be no change In the policy of performing elective intracardiac repair before age 2 years and primary repair rather than pulmonary arterial banding when operation is required in the early months of life.