Pain relief after tonsillectomy is an important part of post-operative management. There are some common drugs and local anesthetics such as bupivacaine used to treat postoperative pain. This research was aimed to assess the role of local injection of bupivacaine in the management of pain after tonsilectomy surgery 96patients aged 5–12 were included in a double-blind clinical trial prospective study. Patients in treatment group received an injection 3cc of 0.5% bupivacaine solution in side and upper peritonsillar areas, and patients in group B were injected 3cc of normal saline in the same area. Patients were asked to Visual Analog Score, After tracheal extubation, 1st, 2th, 4th, 8th,12th, and 24th hours after operation. The first request for analgesic and the total amount of analgesic consumption was also recorded. Regarding to Visual Analog Score over a 24-h period, there was a significant difference between two groups (p<0.05). Also demand for analgesic in 24 hours after surgery was significantly less in treatment group than in placebo (p<0.001). preoperative local 0.5% bupivacaine injection in tonsillectomy patients was effective relieves the post-tonsillectomy pain and significantly reduces opioid consumption in kids.