Background: Sonographic assessment of amniotic fluid has formed an integral and important component of pregnancy assessment of fetal wellbeing. Changes in amniotic fluid volume are associated with variable outcome of the fetus. Amniotic fluid index which is an objective means of assessing adequacy of amniotic fluid volume does not only vary with gestational age but also differs from population to population. Objective: This study was to determine normal reference values of amniotic fluid index throughout gestation in uncomplicated singleton pregnancies among women attending our antenatal care facility. Methods: This was a longitudinal prospective assessment of amniotic fluid index in eighty six healthy pregnant women with singleton pregnancies recruited at 20 to 22 weeks of gestation and followed up to delivery or 41 weeks and 3 days. The patients recruited at 20 weeks had amniotic fluid measurements at recruitment and 4 weeks apart until delivery or 40 weeks gestation. Those recruited at 22 weeks had it also at recruitment and 4 weekly with the last estimation at 41 weeks + 3 days. These measurements were plotted against their respective gestational ages. The data was then analysed using statistical and graphical packages of SPSS version 21. The study populations mean, 5th, 50th and 95th percentiles was documented and discussed appropriately.