This study aims to know the influence of esmolol on requirement of inhalational agent using entropy and also to assess the effect on immediate postoperative pain score. MATERIALS AND METHODS This study was conducted in 60 healthy ASA I and II patients. INCLUSION CRITERIA Body mass index (BMI) which is less than 25, age between 25 to 60 years of either sex who underwent lower abdominal surgeries. EXCLUSION CRITERIA Patients with history of allergy to opioids or halogenated anaesthetics, or taking drugs known to influence anaesthetic requirement including beta blockers, opioids, pregnant women and those who had cardiovascular, pulmonary, renal, hepatic diseases were excluded. Patients were divided into two groups, Group A and Group B depending on the infusion being used, esmolol in Group A and saline in Group B. RESULTS Age, body weight, ASA physical Status, total duration of surgeries (min.) and total isoflurane used was compared in both the groups and was non-significant (P>0.05). Pain was assessed in all the patients when they reached the postoperative room after extubation. VAS0 being the pain score at the time when they reached the postoperative room and VAS5, 10, 15, 20, 25 and 30 being the pain scores at respective time intervals which revealed a statistically significant difference in the VAS score between the groups at 5 and 10 min. intervals. Dose of morphine used at 5, 10, 15, 20, 25 and 30 min. for pain relief was calculated for both the groups and compared. Similarly, there was a statistically significant difference in morphine consumption at 5, 10, 25 and 30 min. intervals (P<0.05). Total dose of morphine used in 30 min. was also significantly less in Group A as compared to Group B (P<0.05). CONCLUSION Esmolol has no effect on requirement of isoflurane, but it decreases the postoperative requirement of morphine and postoperative pain without increasing the risk of awareness as concluded from this study.