Background: Neonatal sepsis a major health challenge associated with major morbidity and mortality. Neonatal care improved recently. However, different challenges regarding management still exist. Vitamin D deficiencies was proposed as a predictor of neonatal sepsis. Objective: To highlight the impact of vitamin D levels on early onset sepsis in full term neonates. Methodology: This is a case control which carried out at the neonatal intensive care unit of Al-Azhar university hospital (Damietta), from March to April 2019. It included 50 full-term neonates with probable sepsis and 50 healthy controls of matched age and sex with no signs of sepsis. Results: vitamin D level showed significant negative correlation with sepsis, Creactive protein (CRP), positive blood cultures; and significant positive correlations with Apgar score, hemoglobin concentration and platelets count. Regression analysis revealed that, higher CRP and lower vitamin D were associated risks of neonatal sepsis in univariate analysis. Multivariable regression analysis revealed that only lower vitamin D level is the predictor for early neonatal sepsis. Conclusions: Vitamin D levels were significantly lower in septic neonates with high sensitivity and specificity. Vitamin D supplementation to mothers during pregnancy could prevent early onset neonatal sepsis.