Background: Hemorrhoids are a common condition that presents with bleeding per rectum, pain at rest and defecation, mucosal discharge, and prolapse. Surgical Hemorrhoidectomy is the treatment method of choice for Grade 3 and Grade 4 hemorrhoids. Hemorrhoidectomy is associated with postoperative pain and no single surgical technique has been proved to significantly reduce the pain. We analyzed in our study the effect partial lateral anal sphincterotomy with hemorrhoidectomy on post-operative pain, early recovery, better wound healing, decreased analgesia requirement in post-operative period, improved quality of life through lesser duration of stay and faster wound healing. Aims: This study aimed to assess the effect of internal sphincterotomy on postoperative pain in patients undergoing hemorrhoidectomy. Methods: This is a randomized, prospective and comparative study included 68 cases of Grade 3 and Grade 4 hemorrhoids who were scheduled for surgical management. The patients were classified randomly into two groups with an equal number of participants. Group A underwent Milligan and morgan open hemorrhoidectomy along with partial lateral anal internal sphincterotomy and Group B underwent Milligan and morgan open hemorrhoidectomy alone. Postoperative pain was recorded using Visual Analog Scale (VAS) score at four time period namely 6 hrs post-surgery, 24 hrs post-surgery, 7 days post-surgery and one month post-surgery. Post-operative analgesia requirement, Anal incontinence, anal stenosis, wound healing, constipation, duration of hospital stay. Results: Patients who underwent Partial Lateral Anal Internal Sphincterotomy with Open Hemorrhoidectomy showed a significant reduction in postoperative pain. Postoperative analgesia requirement, anal stenosis, wound healing, constipation, duration of hospital stay found to be reduced with partial lateral anal internal sphincterotomy. Conclusion: From our study, we conclude that performing a partial lateral anal sphincterotomy in Milligan and morgan open hemorrhoidectomy reduces postoperative pain and aids in early recovery, better wound healing, decreased analgesia requirement and improved quality of life through lesser duration of stay in hospital and faster wound healing.