This study was designed to observe the haemodynamic changes, recovery status and cost effectiveness during anaesthesia in laparoscopic cholecystectomy with medical air in comparison to anaesthesia with nitrous oxide associated with maintain of adequate analgesia and was conducted in the department of Analgesia and Intensive Care Medicine, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh from January 2017 to June 2017. Nitrous oxide is popularly using as an analgesic in current balanced general anesthesia in addition carrier agent for anesthetic. Intraoperative pain intensity depends on many variables including, type of surgery, surgical stimulation and surgical incision. It is difficult to measure intraoperative pain properly under general anesthesia therefore anesthetist depends on the surrogate marker of inadequate analgesia like raised heart rate, blood pressure, sweating and lacrimation. However, unfortunately, these parameters may changes in same direction with light plane of anesthesia, hypercarbia and ongoing procedural status of the patient.