The mortality rate of infants who require renal replacement therapy after surgical repair of congenital heart disease has been reported to be 30%–79%. We report our experience with early initiation of continuous manual peritoneal dialysis (CPD) to treat fluid overload in 20 consecutive critically ill children who underwent CPD post cardiotomy. CPD catheters were inserted at the discretion of the cardiothoracic surgeon. CPD was started for evidence of total body fluid overload with inadequate urine output, and stopped when negative fluid balance was achieved and urine output improved. Median age was 10 days (range 3–186 days), mean time to start CPD post-operatively was 22 h (range 5–40 h), and mean duration of CPD was 50 h (range 13–92 h). CPD resulted in mean ultrafiltration of 93 ml/kg per day (range 43–233 ml/kg per day). Net negative fluid balance was 106 ml/kg per day (range 49–273 ml/kg per day). During CPD, the mean number of inotropes decreased from 2.2 to 1.6 (PP<0.01). No patient died during CPD or had CPD discontinued due to adverse hemodynamic effects. The overall mortality rate was 20%. We conclude that early initiation of CPD can safely and effectively promote fluid removal in infants after repair of congenital heart disease, with a lower mortality rate than has previously been reported.