Introduction: Oligohydramnios or decreased amniotic fluid volume (AFI<5cm) is associated with adverse maternal & Pregnancy outcome. Amniotic fluid is a very complicated yellowish fluid located between the amniotic sac and the fetus. Oligohydramnios is associated with adverse Pregnancy outcome in the form of meconium staining, intrauterine growth restriction (IUGR), caesarean section for abnormal fetal heart rate tracing, low Apgar score and neonatal intensive care unit (NICU) admission. Objective: To evaluate the pregnancy outcome of oligohydramnios and borderline amniotic fluid index. Methods: This was a prospective study was carried out at Department of Obstetrics & Gynaecology, Rangpur Medical College & Hospital, Rangpur, Bangladesh from January 2022 to June 2022. Total number of sample size will be taken 100. Among them 50 patient of oligohydramnios and 50 patients with borderline amniotic fluid index will be taken as group-A & group-B respectively. 100 singleton pregnancies beyond 28 weeks of gestation with AFI< 8 cm, delivered within seven days of admission. Patients were divided in two groups, those with AFI ≤ 5 cm and borderline AFI of 5.1 to 8 cm. Pregnancy outcome was studied in the form of onset of labor, mode of delivery, fetal heart rate variations, meconium staining and lower segment caesarean section (LSCS) for fetal distress, Apgar score, birth weight, NICU admission and neonatal mortality. Results: Amongst the study group, 50% of cases had oligohydramnios (AFI ≤5 cm) as against 50% with marginal or borderline AFI. There was no statistical difference in age, parity and gestational age in both the groups. The mean amniotic fluid index in the first group with AFI ≤5 cm was 3.48±1.10 and that of second group with AFI of 5.1 to 8 cm was 6.69±0.75. On comparison of mode of delivery in between both the groups, a statistically significant difference was observed for caesarean section in oligohydramnios with AFI ≤ 5 cm group compared to AFI of 5.1 to 8 cm group. Patients with oligohydramnios with AFI ≤5 cm were significantly associated with IUGR and presence of abnormal umbilical artery Doppler velocimetry (p <0.05). Adverse Pregnancy outcome was seen in higher percentage of patients having AFI ≤5 cm than with borderline AFI. The difference was statistically significant for overall caesarean delivery rate and LSCS for fetal distress (p <0.05). Conclusion: An amniotic fluid index of ≤5 cm is commonly associated with intrauterine growth restriction and abnormal umbilical artery Doppler velocimetry studies. Adverse Pregnancy outcome is seen in higher percentage of patients having oligohydramnios than that of borderline AFI. Statistically significant difference for overall caesarean delivery rate as well as LSCS for fetal distress mandates the need for close antepartum and intrapartum monitoring.