Shivering during surgery is a relatively frequent consequence. Although perioperative shivering and its impacts are well understood, prophylaxis is often disregarded. In order to assess the effectiveness and safety of meperidine, low-dose ketamine, magnesium sulphate, and ondansetron in avoiding perioperative tremor in patients having transurethral resection of prostate under subarachnoid block, this research was conducted. Method: In this randomized controlled investigation, 200 patients aged 60 to 70 years were divided equally into one of four groups. meperidine 0.3mg\kg (group M), Ketamine 0.25 mg\ kg (Group K), magnesium sulphate 40mg\kg diluted in 100ml normal saline over 10min. (Group MS), and Ondansetron 0.1 mg\kg (Group O). There have been reports of side effects including hypotension, sedation, nausea and vomiting, hallucinations, and respiratory depression. Results. Postoperative shivering (POS)was observed in 8 (16%), 10 (20%), 22 (44%), and 26 (52%) of group M, K, MS, and O, respectively. The frequency of hypothermia did not vary across groups (P = 0.217). There were no discernible intergroup variations in the prevalence of bradycardia (P=0.190). In the K group, there were considerably fewer cases of hypotension (8%). Sex, and two patients from groups MS and K, respectively, had RAMSAY sedation scores of 4 recorded. In group K, 4%,12%, and 12% of the patients were found to have headache, hallucination, and nystagmus respectively. In none of the four research groups was there a case of respiratory depression. Conclusion. Low-dose meperidine, low-dose ketamine, magnesium sulphate, or ondansetron given as a preventative measure all had a strong anti-shivering effect with few side effects. Low dosage ketamine, however, has the benefit of being less likely to cause hypotension, nausea, and vomiting than meperidine