Children under 5 years of age in developing countries are particularly vulnerable to malnutrition. Malnutrition affects 50% of hospitalized children and 25–70% of the critically ill children. Malnutrition interferes with the appropriate response of the body to disease and predisposes to infection and to the onset of multiorgan failure, increasing morbidity and mortality, the mean length of hospital stay, and health costs. Aim: A prospective cohort study of children admitted to the tertiary pediatric ICU between January 2009 and January 2014 was carried out. To assess the malnutrition type, and impact of nutritional status on outcomes like mortality rate, disease, complication in critically ill children.To the study were enrolled 138 children admitted to the pediatric intensive care units of the NationalCenter for Maternal and Childrens Hospital. The study protocol was approved by the Ethics Committee of the MNUMS, and written informed consent was obtained from all study participants. Nutritional status was determined using Waterlow criteria.Total participants were 49.3% (n=68) of male, 50.7% (n=70) female. 138 children with a mean age 4.4 months ±3.6/ Std.Er/, min = 1 month, max = 12 months, mode = 1 month. n=70(50.7%) acute malnutrition, n=58(42%) chronic malnutrition by Waterlow criteria. In malnutrition group was assessed patient with ricket n=36 (26.1%), patient with anemia n=56(58.9%)While malnutrition is a major problem in pediatric intensive care units. Acute malnutrition moreoccurred in the pediatric intensive care.Malnutrition more occurring of intrauterine infection, genetic disorder, hematology disease’s patients.