Introduction: Fentanyl is a potent short acting synthetic opioid agonist which is similar to morphine and confers analgesic effect at a greater extent. Fentanyl targets opioid receptors present in brain neuroanatomical structures that better hold the speaking, pain and emotions and so on. Aim: The main aim was to study and compare the effects of fentanyl at varying time intervals before anaesthesia induction on haemodynamic response to laryngoscopy and endotracheal intubation and side effects of the drugs in patients undergoing surgical procedures under general anaesthesia. Materials and Method: Study population (50 patients) was randomly divided by computer generated numbers into 2 groups with 25 patients in each group. Group F5: received Inj. Fentanyl 2µg/kg 5 min before Anaesthesia induction. Group F10: received Inj. Fentanyl 2µg/kg 10 min before Anaesthesia induction. Standard monitors like ECG, NIBP, and pulse-oximeter were applied and baseline parameters [SpO2, Heart rate (HR), Systolic blood pressure (SBP), and Diastolic blood pressure (DBP), Mean arterial pressure (MAP)] were recorded. Results: The difference in mean HR, systolic blood pressure, mean diastolic blood pressure, mean arterial pressure were increased compared with baseline and statistically highly significant with p value of <0.0001after anaesthesia induction, 1min, 2min, 3min, 5min and 10min of endotracheal intubation. No significant changes occurred in HR, SBP at baseline and after premedication inn between the groups. An increase in the HR, SBP was observed in both the groups after intubation However, in group F5 the increase was seen to a lesser extent and lower compared to group F10 at all time points. The changes observed with regard to DBP, MAP and RPP were same as that seen in SBP, indicating that successful suppression of stress response was achieved in group F5. Conclusion: Our results indicated that 5 minutes prior to induction was the most effective injection time of fentanyl at a dose of 2 mcg/kg to prevent the hemodynamic responses to tracheal intubation.