Supine percutaneous nephrolithotomy (PCNL) is an advanced minimally invasive surgical technique for managing large, complex renal calculi, offering distinct advantages over the conventional prone approach. This chapter examines the anatomic and procedural benefits of the supine position, including enhanced anesthetic safety, improved respiratory mechanics, and easier access for combined endoscopic procedures. Key aspects of patient positioning, renal access strategies, tract dilation, and stone fragmentation techniques are explored, alongside considerations for complications, postoperative outcomes, and comparative efficacy. The chapter also discusses technological advancements, fluoroscopic guidance, and adjunctive measures that optimize stone clearance and patient recovery.