In Pakistan, neonatal mortality and morbidity are remarkably high. Birth asphyxia (perinatal asphyxia) is one of the main contributors to this, apart from prematurity, sepsis and other causes. Objective: To assess the effectiveness of magnesium sulfate in term neonates having perinatal asphyxia Methods: This Randomized Controlled Trial was carried out at the Department of Pediatrics, Sheikh Zayed Hospital Rahim Yar Khan from July 2023 to December 2023. The overall sample size was 130 patients (65 patients in each group). Neonates in group A received MgSO through I/V, 3 doses 250mg/kg/dose, 24 hours apart along with standard treatment. Group B was a control group that received 20 ml of normal saline infusion at the same interval with similar supportive and symptomatic treatment with regular monitoring. The outcome in terms of mortality, seizure, early initiation of feed, time to the establishment of full oral feeding, duration of seizures and duration of hospital stay were assessed. All the data was analyzed by using SPSS version 25.Results: In the current study, a total of 130 neonates were enrolled. Among them, moderate asphyxia was observed in 90 (69.23%) patients whereas severe perinatal asphyxia was observed in 40(30.77%) patients. In group A, the mean level of serum magnesium in neonates with moderate asphyxia was 2.81 (±0.20) mEq/L while in neonates with severe asphyxia, it was 2.89 (±0.61) mEq/L. The moderate asphyxia patients in group-A showed significant statistical improvement in terms of seizure control (hours) (14.11±1.22 vs 18.11±1.56; P=0.01), normal cry appearance (Days) (11.1±0.12 vs 13.11±1.29; p=0.03), normal activity appearance (Days) (11.9±0.02 vs12.00±1.51; p=0.01), full oral feed acceptance by sucking (Days) (13.31±0.99 vs 14.61±1.51; p=0.01) and mean hospital stay duration (Days) (14.99±1.66 vs 16.21±1.11; p 0.02). Conclusion: Our study concludes that in asphyxiated newborns, postnatal magnesium sulphate infusion is safe and likely to enhance the short-term neurological prognosis in cases with moderate-grade encephalopathy.