Background: The most common causes of prenatal morbidity and death in Bangladesh are eclampsia and severe preeclampsia or toxemia (PET). Obstetricians and anesthesiologists have complex challenges while dealing with this condition. Despite the improved result of spinal anesthesia over general anesthesia, general anesthesia is still routinely used for emergency LUCS in underdeveloped nations. More and more people in industrialized nations, such as the United Kingdom and the United States, recognize spinal anesthesia for its safety. Objective: In this study our main aim is to evaluate the efficacy of the Spinal Anesthesia during Emergency Cesarean Section for Severe Preeclampsia and Eclampsia Patients. Method: This cross-sectional study was carried out at tertiary medical hospital from January 2020 to January 2021. Total 200 cases of severe PET (n=110) and eclampsia (n=100) patients were selected by subarachnoid block for emergency LUCS. Each patient was given magsulph as prophylactic or maintenance dose and judiciously preloaded by crystalloid fluid. Results: Most of the patients belong to 31-40 years age group, 55% and 95.8% cases were multigravida. In severe PET group, intraoperative hypotension was observed in 32% cases and postoperative period hypotension was observed in 8% cases. Whereas preeclampsia group, intraoperative hypotension was observed in 31% cases and postoperative period hypotension was observed in 9% cases. In addition, maternal morbidity where acute renal failure seen in 5%, syndrome 7%, DIC 7%, abruptio placentae 12%, pulmonary edema 4%, septicemia 13%, PPH 10% and postpartum eclampsia 15%.In severe PET group, 21% cases transferred to eclampsia ward, followed by 9% shifted to ICU, 1% case was expired. Whereas, in preeclampsia group 20% cases transferred to eclampsia ward, followed by 8% shifted to ICU, 2% case was expired. In eclamptic group 7% cases were transferred to NCU, whereas 8% had PET. Neonatal mortality was observed in 3% cases. p value was found 0.000 which is very highly significant. Conclusion: With close monitoring of perioperative events, spinal anesthesia may be used as a safe alternative technique to GA or epidural in severe preeclampsia and eclampsia, even in cases of altered consciousness or restlessness in the presence of an expert and skilled anesthesiologist, reducing perioperative maternal and neonatal morbidity and mortality.