Bispectral Index (BIS) was introduced by Aspect Medical Systems, Inc in 1994 as a novel measure of level of consciousness by algorithmic analysis of patient’s encephalogram during anaesthesia. Besides providing an idea about the hypnotic state of the patient, it also enables titration of anaesthetic agents so as to avoid adverse effects as awareness and side effects of over doses. The ideal sedative medication should provide an early titrable level of sedation, predictable amnesia, decreased anxiety and a rapid recovery with minimal side effects. In the present study, 60 patients of either sex belonging to ASA grade I and II between age range of 20­60 years posted for elective operative procedures performed under spinal anaesthesia were selected. All these patients were preanaesthetically evaluated and written valid consent was obtained. All monitors were attached and baseline parameters as pulse rate, mean arterial pressure, respiratory rate and SpO2 were noted. These 60 patients were divided into 2 equal groups of 30 patients each. In Group M, Midazolam 1% intravenous infusion in 5% Dextrose was started in dose of 0.5mg/kg/hr till BIS value more than 75 was maintained with infusion via syringe pump at 65­85 range and In group P, Propofol 1% infusion in 5% Dextrose was started in dose of 6mg/kg/hr. Intraoperatively, mean pulse rate, mean arterial pressure, respiratory rate, SpO2 were monitored and noted at various time intervals. These patients were monitored intra and postoperatively for any side effects These patients were evaluated for time taken to reach required level of sedation, time taken for recovery, dose required for level of sedation, haemodynamic stability and Alderate score. It was observed that, there was no significant difference in groups M and P at various time intervals but there was statistically significant difference in mean pulse rate, mean arterial pressure amongst the groups at various time intervals, When compared to baseline readings. This difference was more significant in Propofol group as compared to Midazolam group. BIS value in both groups at various time intervals, there was significant difference. Mean time taken to reach required level of sedation was significantly greater in group M as compared to group P. Mean time taken for recovery in group M was significantly greater as compared to group P. The incidence of dreadful complications was comparatively less in both groups. Mean Alderate score on arrival in recovery room in both groups was significant and insignificant at 1 hour.