The practice of modern anesthesiology has been developed from intraoperative period into perioperative period. Postoperative Pain management is one of the most important components of adequate post-surgical patients care. This article wrote with the aim of emphasis on importance and effectiveness of post-operative Pain management. Reading this article is beneficial for physicians, interventional Pain managers and who care about Pain medicine. Unrelieved acute Pain after surgery usually elicits pathophysiologic neural alterations, including not only peripheral but also central sensitization which evolves into chronic Pain syndromes. The main purpose of perioperative Pain control is providing an adequate comfort level and acceptable side effects for patients. Effective postoperative analgesia improves patients’ outcome as observed by early ambulation, decrease in side effects, and reduce the incidence of postoperative chronic Pain (1-3).