Over a period from May, 1977 to SEptember, 1982, 101 cases ofopen heart surgerywere done under cardiopulmonary bypass. There were 50 male and 51 female patients, and the ages of the patients ranged from 19 months to 48 years. Sixty-nine cases were congenital heart disease and 32 cases were acquired heart disease, which consisted of 30 valvular disease, 1 IVC obstruction, and 1 myxoma. Among the 30 cases of valvular disease, 12 MVR, 4 MVR+TAP, 2 MVT+AVR, 1 MAP, and 11 OMC were done. There were 3 operative deaths (17.5%) in 16 MVR, 1 in 2 MVR+AVR, and 1 in 11 OMC. Operative mortality in 69 congenital heart disease was 13.0% ; 3 deaths (6.7%) in 45 acyanotic and 6(25.0%) in 24 cyanotic cases. The overall mortality for 101 cases was 14.8%; 13.0% for congenital and 18.8% for acquired heart disease.