Background: Vitamin D is a hormone that affects a wide range of functions within the body. Neonatal hypoxic ischemic encephalopathy (HIE) is a serious disease that may lead to permanent brain injury. Objective: The present study aimed to study vitamin D status in hypoxic ischemic in encephalopathy. Patients and methods: A case control study carried out in newborn intensive care unit (NICU) of Zagazig University Children Hospitals. Total number of cases that met the inclusion and exclusion criteria was 49 full term neonates with HIE divided according to Sarnat stages: stage I; 20 full term neonates, stage II; 15 full term neonates and stage III; 14 full term neonates. Cases were compared to 16 healthy controls. Results: There was a statistical significant increase in Apgar score 1, 5, 10 in control group compared to all cases groups. There were no statistical significant differences between the studied groups in relation to CBC results. There was a statistical significant difference between the different stages of HIE in CRP and pH.There was a statistical significant increase in frequency of hypoxic change in stage III compared to stage II and I. All stages of HIE showed statistical significant increase in frequency of vitamin D deficiency compared to control group. Stage III had statistical significant increase in frequency of vitamin D deficiency compared to stage I and II. Conclusion: Serum 25(OH) vitamin D insufficiency is present in the majority of term HIE neonates. 25 (OH) vitamin D was significantly deficient in stage III more than stage I and II.