Background: Parecoxib has been previously evaluated in various doses to reduce post-operative pain relief. Aim of the Study: Parecoxib was evaluated as a pre-emptive agent in patients undergoing surgery under general anesthesia and hemodynamic effects and side effects. Settings and Design: This study design was a double blind prospective randomized controlled trial. Patients and Methods: 100 patients in age group 20–45 years undergoing surgery under general anesthesia were randomly divided into two Groups. Group I received 40 mg of Parecoxib I.V. 1 hour before induction of anesthesia and 2 ml normal saline I.V. at the end of surgery and Group II was given the same vice versa. Hemodynamic parameters i.e., blood pressure and pulse rate, intensity of pain and number of patients requiring rescue analgesia in two groups at baseline and post-operatively at the end of surgery and henceforth at 30 minutes, 1, 2, 4, 6, 8, 12 hours were noted in addition to adverse effects in two Groups. Results: Demographic profile and hemodynamic parameters were comparable at baseline in two Groups. The mean time weighted score of pain intensity was significantly higher in Group II (1.92 ± 0.10) as compared to Group I (1.61 ± 0.34). Pain relief score was significantly lower in Group II (1.13 ± 0.18) as compared to one (1.72 ± 0.56). They demanded rescue analgesia at a relatively early time 125.40 ± 111.87 min as compared to Group I patients 357.24 ± 231.37 min ( t:6.379, p:0.000). Post-operatively the mean of hemodynamic parameters over varied time intervals was slightly higher in Group II as compared to Group I. Conclusion: Pre-operative parecoxib has an effective pre-emptive analgesic effect by decreasing the post-operative pain and delaying the time to demand of rescue analgesia as compared to its use post-operatively.