Extracorporeal membrane oxygenation (ECMO) is a lifesaving therapy for patients with cardiopulmonary failure after cardiac surgery. Fluid overload (FO) is associated with increased morbidity and mortality in this population. We present our experience using peritoneal dialysis (PD) as an adjunct for fluid removal in eight consecutive neonates requiring ECMO after cardiac surgery between 2010 and 2012. PD was added to FO management when fluid removal goals were not being met by hemofiltration (HF) or hemodialysis (HD). Percent FO was 36% at ECMO initiation; 88% (seven of eight) achieved negative fluid balance before discontinuation of ECMO. PD removed median 119 mL/kg/day (interquartile range [IQR], 70-166) compared with median 132 mL/kg/day (IQR, 47-231) removed by HF/HD. PD and HF/HD fluid removal were performed concurrently 38% of the time. Unlike HF/HD, PD was never stopped secondary to hemodynamic compromise. Median duration of ECMO was 155 hours (IQR, 118-215). Six of eight patients were successfully decannulated. These results suggest PD safely and effectively removes fluid in neonates on ECMO after cardiac surgery. PD may increase total fluid removal potential when combined with other modalities.