Background: Vitamin D deficiency is a common endocrinological problem. Maternal vitamin D insufficiency during pregnancy has been associated with many pregnancy-related complications like preeclampsia, gestational diabetes (GDM), preterm labor, and low birth weight (LBW). Maternal vitamin D deficiency can lead to poor skeletal growth and reduced bone mineral density in children. Aims and objectives: To study the prevalence of vitamin D deficiency in antenatal women and to study an association between vitamin D deficiency and maternal and neonatal complications. Materials and methods: A prospective study of 100 antenatal women presenting to obstetrics and gynaecology OPD at GSMCH, Banur. Out of these, data from 94 women were finally analyzed. For the rest of the women, follow-up and intrapartum and neonatal details were not available, so they were excluded from the study. Results: The prevalence of vitamin D deficiency in the present study was 79.8%. The rate of small for gestational age babies (SGA) and oligohydramnios was significantly higher in the study group. There was no significant difference in the incidence of GDM, preterm labor, and preterm premature rupture of membranes (PTPROM). Conclusion: Antenatal vitamin D deficiency is associated with hypertensive disorders of pregnancy (HDP), SGA, oligohydramnios, and LBW. So, routine vitamin D supplementation should be recommended in the antenatal period.