Pain due to surgical and diagnostic procedures in infants and children is usually undiagnosed and undertreated due to lack of awareness among physicians and paucity of experience in treating it. This chapter touches upon the reasons and ethics behind the need to treat perioperative pediatric pain and includes relevant age-appropriate tools to assess it. Both non-pharmacological and pharmacological methods are being utilized to manage this pain. Use of newer modalities like ultrasound-guided regional blocks and non-opioid analgesics to prevent and reduce dependence upon opioids is also emphasized upon. A good perioperative protocol- to manage physical, emotional and psychological aspects of pain in children prevents long term complications like chronic pain, behavioral issues and mental disorders.