Background: Preterm birth constitutes 5-18% of all deliveries and very low birth weight infants comprise 4-8% of all live births. Significant advances in neonatal care have increased the survival rate of premature infants. However, the associated morbidity continues to affect these infants despite the increased survival rate. Preterm birth is the most important problem in modern obstetrics. More than 1 million infants born preterm (at less than 37 weeks of gestation) died worldwide, making it the second leading cause of death in children under the age of 5 years. Aim: The aim of this work was to study the role of vitamin D in Egyptian pregnant women at labour to evaluate its predictive value in preterm labour. Methodology: This study was conducted on 90 subjects of pregnant females at labor. Their ages ranged from 14 to 40 years old. This study was carried out in collaboration of the Clinical Pathology and Obs/Gyna Departments at Al-Hussein and Bab-Elshareyia University Hospitals, Faculty of Medicine, Al-Azhar University. All participants were selected from the Obs/Gyna Department, Al-Hussein and Bab-Elshareyia University Hospitals over a period from April, 2018 to July, 2018. In the present study an attempt was done to determine whether the level of vitamin D in Egyptian pregnant females correlates with preterm labor or not. Results: Group 1 (study group): Mean vitamin D level is 10.93 ng/ml. 27 patients of this group (60%) were suffering from vitamin D deficiency while the other 15 (33.3%) suffered from vitamin D insufficiency and other 3 (6.6%) had normal vitamin D level. Group 2 (control group):.Mean vitamin D is 16.15 ng/ml. This study showed highly statistically significant decrease (p value <0.001) in vitamin D in the study group as compared to control group. 93% showed abnormally low 25-(OH) D levels for cases having preterm labor where 60% of patients shows deficient 25-(OH) D (<12 ng/ml), 33% of patients showed insufficient 25-(OH)D (>20 and <30 ng/ml), while 7%of cases showed normal vitamin D level. Conclusion: Vitamin D deficiency occurs in the majority of preterm labour cases in Egypt and therefore decreased serum vitamin D levels are considered an additional risk factor in the pregnancy outcome. Recommendation: For better assessment of vitamin D status, future studies should be done to evaluate serum levels of Ca, Ph and PTH to assess the cause of deficiency, which will help in better management. In addition, it is recommended to consider vitamin D supplementation and its efficacy as a new important line of prophylaxis in pregnant females. Thereby prophylactic administration of vitamin D could be useful and researches have to be done to approve this theory. Screening for vitamin D deficiency seems of value in pregnant females.