Protein-losing enteropathy (PLE), defined as severe loss of serum protein into the intestine, occurs in 4% to 13% of patients after the Fontan procedure. We report a case of PLE reversal after heart transplantation in a 14-year-old boy with Fontan circulation who previously was treated unsuccessfully with medical therapy. The protein loss continued after heart transplantation. We administered total parenteral nutrition to rest the bowel. After 16 months, we observed a gradual,decrease in protein loss. The patient is doing well 5 years after heart transplantation and had has a normal serum albumin level.