Protein-energy malnutrition (PEM) is a significant cause of morbidity and mortality for patients receiving maintenance hemodialysis. Minimal study has evaluated therapeutic options for and biochemical marker assessment of pediatric patient PEM. In 2001, we expanded the indications for intradialytic parenteral nutrition (IDPN) treatment of PEM to all maintenance hemodialysis patients, regardless of etiology, who had a >10% weight loss and were at less than the 90th percentile of ideal body weight. Nine patients received thrice weekly IDPN from 3 to 22 months with minimal side effects. Six patients had weight and body mass index increase, 1 patient stopped losing weight, and 2 patients continued to lose weight during the initial 5 months of IDPN therapy. Cohort subanalysis showed that all patients with organic PEM responded to IDPN therapy, whereas patients with psychosocial causes of PEM did not. The normalized protein catabolic rate increased significantly for patients whose condition responded to IDPN therapy, whereas serum albumin did not change. The current study suggests that IDPN is effective treatment of organic causes of PEM in pediatric patients receiving maintenance hemodialysis and that normalized protein catabolic rate may be superior to serum albumin as a marker of nutrition status. The observation that IDPN was not sufficient to reverse PEM in patients with psychosocial PEM causes should direct caregivers to address the relevant underlying causes as well as to provide intensive nutrition therapy.