INTRODUCTION: Spinal anaesthesia significantly impairs the thermoregulation system by inhibiting tonic vasoconstriction, which plays a significant role in temperature regulation. It also causes a redistribution of core heat from the trunk (below the block level) to the peripheral tissues. These factors predispose patients to hypothermia and shivering. The present study aims to compare the efficacy of I.V. Tramadol, and I.V. Dexmedetomidine in the treatment of post spinal anaesthesia shivering in patient undergoing infra umbilical surgeries. MATERIAL AND METHODS: A prospective randomised comparative study was conducted after institutional ethical committee’s approval on 60 patients of ASA grade 1 and 2 who developed shivering of grade 3 and 4 after spinal anaesthesia. Patients were randomly allotted in to two groups, namely group T(n=30) who received Tramadol 0.5mg/kg i.v. and group D (n=30) who received dexmedetomidine 0.5µg/kg i.v. Vital parameters of the patient such as Heart rate, Blood pressure, SPO2, RR and temperature were monitored at regular intervals and noted. Onset of shivering, time taken to stop shivering, recurrence of shivering and side effects like nausea, vomiting, bradycardia, hypotension and sedation were also noted. RESULTS: The mean temperature at which patient in group T developed shivering was 36.22±0.190C and in group D was 36.27±0.160C (p > 0.05). The mean duration of shivering to occur following spinal anaesthesia was also comparable in both the groups. Both the groups had 100% response rate in controlling the shivering. Mean time required for cessation of shivering after treatment was 5.48±0.50 minutes in group T and 2.83±0.42 minutes in group D (p < 0.05). CONCLUSION: Both dexmedetomidine and tramadol are effective in treating patients with post–spinal anaesthesia shivering, but time taken for complete cessation of shivering was shorter with dexmedetomidine as compared to tramadol, the difference being statistically significant. Furthermore, dexmedetomidine causes fewer adverse effects like nausea and vomiting.