BACKGROUND: Vitamin D deficiency during pregnancy has important health implications for the mother and infant. Vitamin D deficiency is very common and high in pregnancy and breastfed infants, ranging from 46% - 90.3% and 81% - 90.3% respectively. Recent studies have shown a staggering increase in the prevalence of vitamin D deficiency, and very high prevalence rates of vitamin D deficiency have been recorded in pregnant women and their neonates in India. The prevalence of vitamin D deficiency in Nigerian pregnant women is unexplored necessitating the need for this study. This study will serve as a basis for further studies on vitamin D in pregnancy and in the neonates. OBJECTIVE: To determine the prevalence of vitamin D deficiency among pregnant women and their newborns at Lagos University Teaching Hospital. METHODOLOGY: This was a prospective cross-sectional study on pregnant women in the peripartum period at term and their neonates. A total of 179 pregnant women were recruited for the study. With pro forma, socio-demographic information was obtained, as well as information on the use of vitamin D supplements during pregnancy, the number of daytime hours per day spent outdoor, dressing style; whether covered or uncovered and the type of subjects’ skin complexion, after obtaining written consent. Samples of maternal and cord blood were collected on the day of delivery. Serum level of 25(OH)D was determined using the CALBIOTECH Vitamin D ELISA kit according to the kit’s instructions. Data were analyzed using SPSS version 15 statistical software package.