Introduction: Shivering is one of the most common complications during spinal anesthesia , leading to patient discomfort and increased metabolic demand. This is a result of blocked sympathetic activity with effective vasodilatation, leading to loss of thermoregulation. This study aimed to compare the efficacy of prophylactic pethidine and tramadol in preventing shivering in patients undergoing spinal anesthesia. Aims and Objective: To analyze the outcome of prophylactic Tramadol hydrochloride and Pethidine hydrochloride for shivering patients who underwent elective surgery under spinal anaesthesia. Method: This prospective, randomized double blinded study, was conducted in 120 ASA 1 and ASA 2 adult patients of either gender scheduled for elective surgery and spinal anaesthesia. Patients were allocated into 2 groups of 30 each, to receive either pethidine or tramadol in a dose of 0.5mg/kg 10 min before administration of spinal anaesthesia. Intraoperative hemodynamic Parameters, incidence and severity of shivering were recorded and statistically analysed with t-tests, chi-square tests and ANOVAs. Result: The incidence and severity of shivering was significantly lower in pethidine group compared to tramadol group (p<0.001). However, pethidine is associated with mild sedation score and lower incidence of nausea and vomiting compared to tramadol. Conclusion: Prophylactic pethidine is more effective than tramadol in reducing the incidence and severity of shivering with minimal sedation in patients undergoing elective infra umbilical surgery under spinal anesthesia.