BACKGROUND: In percutaneous nephrolithotomy surgeries post operative pain due to dilatation of the renal capsule, the parenchymal tract and placement of the nephrostomy tube is distressing to the patient. Quadratus lumborum (QL) block and Erector spinae (ESP) block are two emerging myofascial plane blocks that leverage multimodal analgesia to improve postoperative pain control. AIM:To compare the efficacy of ultrasound guided Quadratus lumborum block with 20 ml of 0.25% Bupivacaine and 8 mg Dexamethasone vs Erector Spinae block with 20 ml of 0.25% Bupivacaine and 8 mg Dexamethasone for post operative analgesia in patients undergoing PCNL surgeries under general anaesthesia. METHODS AND MATERIALS: Sixty patients scheduled for percutaneous nephrolithotomy were randomly allocated into two groups QLB and ESPB groups, patients received unilateral (QLBIII or ESPB) respectively, with 0.3–0.4 ml/kg of bupivacaine 0.25%. The primary outcome was the Pain relief by using Visual Analogue Score (VAS), time for the first rescue analgesic (inj. tramadol 2mg/kg I.V), number of rescue analgesics in first 24 hours post operatively, total dose of opioid in 24hrs of post op period. The secondary outcomes were the Hemodynamic parameters, any adverse events in the post operative period.