SummaryBackground Critically ill children are at high risk of underfeeding and AKI, which may lead to further nutritional deficiencies. This study aimed to determine the adequacy of nutrition support during the first 5 days of intensive care unit (ICU) stay. Results Of the 167 patients, 102 were male and 65 were female (median age 1.4 years). Using the RIFLE criteria, 102 (61%) patients had no AKI, whereas 44 (26%) were classified as category R (risk), 12 (7%) as category I (injury), and 9 (5%) as category F (failure). The median 5-day energy intake was lower relative to estimated BMR. Overall protein provision (19%) was lower than energy provision (55%) compared with estimated needs (P,0.001). I/F patients were more likely to be fasted versus receiving enteral/parenteral nutrition (n=813 patient days) and to receive ,90% of BMR (n=832 patient days) than No AKI/R patients.Conclusions Underfeeding, common in critically ill children, was accentuated in AKI. Protein underfeeding was greater than energy underfeeding in the first 5 days of PICU stay. Efforts should be made to provide adequate nutrition in ICU patients with AKI.