Background: The use of neuraxial opioid has gained popularity over the last few years. The dose calculation of local anesthesia for intrathecal block is difficult due to hormonal and mechanical factors of pregnant women along with neonatal outcome. Aim: This study was undertaken to compare the effects on outcome of newborn and peri-operative maternal analgesia with intrathecal versus intravenous fentanyl in lower segment cesarean section under subarachnoid block. Materials and Methods: The ASA I and II pregnant women were randomly allocated into 2 Groups (30 patients each). Group A received 1.7 ml of 0.5% hyperbaric bupivacaine along with 25 mcg fentanyl (0.5 ml), Group B received 1.7 ml of 0.5% hyperbaric bupivacaine along with saline (0.5 ml) 1 mcg/kg body weight of intravenous fentanyl immediately after SAB. Umbilical arterial blood gas analysis was sent immediately after baby extraction and Apgar score noted. The sensory and motor level achieved, hemodynamic changes, post-operative maternal analgesia and side effects were recorded. Results: Apgar score of newborn was normal in both the groups. Patients in Group A had statistically significant prolonged maternal analgesia than a patient in Group B (p <.0001). There was statistically significant (p = 0.002) decreased incidence of nausea and vomiting in Group A. Conclusion: Intrathecal and intravenous fentanyl achieves quality anesthesia with good Apgar score of neonate, while intrathecal fentanyl has added benefit of prolonged peri-operative maternal analgesia with minimal side effects.