Introduction:– Spinal anaesthesia is one of the most popular and safe techniques used for various surgeries. A common problem that develops following spinal anaesthesia is shivering. Shivering is a physiologically stressful and undesirable outcome for a patient although its main role is to provide heat. It may occur in patients receiving regional anaesthesia or general anaesthesia. Shivering is preceded by core hypothermia and vasoconstriction above the level of block. Ketamine has been found to be effective for prevention and treatment of shivering. However, there are few studies regarding the use of midazolam or a midazolam–ketamine combination as a prophylactic agent against intra or postoperative shivering during spinal anaesthesia. So, in the quest for safer and efficacious choice of drug, our study plans to compare i.v. ketamine, i.v. midazolam, midazolam and ketamine in combination, and placebo (saline) for the prevention of shivering in patients undergoing elective surgery under spinal anaesthesia. Material and methods:– This study was conducted at Govt Medical College and Associate group of Hospitals, Kota from jan.2016 to dec.2016. We conducted a double blind, prospective, randomized controlled study of 120 cases from Orthopaedic department between age group 30–60 yrs of both sex. We divided the cases into 4 groups of 30 each, as I. Group K – who received Ketamine (K) 0.5 mg/kg i.v. II. Group M – who received Midazolam (M) 75 ug/kg i.v. III. Group KM – who received Ketamine 0.25 mg/kg + Midazolam 37.5 ug/kg i.v. IV. Group Placebo (P)–who received normal saline (NS) 5 ml i.v. Standard protocol followed to administering regional anaesthesia. Axillary and tympanic temperature readings were taken using a standard procedure. Shivering was graded using a scale similar to that validated by Tsai and Chu. All data were collected and analysed with the help of suitable statistical parameters. Results:– Our study results in that the use of ketamine alone is definitely superior to placebo for the prevention of shivering after spinal anaesthesia. However the combination of ketamine plus midazolam is significantly superior to ketamine alone.