Study Objective: Primary aim was to compare and study the efficacy of intravenous dexmedetomidine (1 μg/kg) and tramadol (1 mg/kg) when used for the control of post-spinal anesthesia shivering. We also compared and studied the hemodynamic changes, complications and adverse effects, in both study groups. Design: Prospective randomised double blind study. Setting: Operating room. Patients: Sixty American Society of Anesthesiologists Grade I and II patients of either gender, aged between 18 and 60 years, scheduled for various surgical procedures under sub-arachnoid block. Interventions: The patients were randomised in two Groups of 30 patients each to receive either 1 μg/kg dexmedetomidine (Group D) or 1 mg/kg tramadol (Group T) as a slow intravenous bolus over 10 minutes, once shivering commenced. Measurements: Grade of shivering, onset of shivering, time for cessation of shivering, recurrence, response rate (complete. Incomplete or failure to control shivering), duration of surgery and spinal anesthesia, axillary temperature, hemodynamic parameters (heart rate, systolic, diastolic and mean arterial pressure, ECG) and adverse effects were observed at scheduled intervals. Results: The mean time taken for cessation of shivering in Group D was 2.55 ± 1.06 minutes, whereas that in Group T was 4.15 ± 1.68 minutes. The difference between the two Groups was analyzed quantitatively and found to be highly significant (p < 0.001). In dexmedetomidine Group, 2 patients had recurrence; whereas, in tramadol Group, 5 patients had recurrence. Conclusion: Both dexmedetomidine (1 mg/kg) and tramadol (1 mg/kg) are effective in treating patients with post-spinal anesthesia shivering. However, dexmedetomidine is more effective as time taken for complete cessation of shivering is shorter with dexmedetomidine as compared to tramadol and incidence of recurrence of shivering is also lower. Furthermore, dexmedetomidine does not cause adverse effects like nausea and vomiting as are seen with tramadol. Sedation caused by dexmedetomidine provides additional comfort to the patient.