Renal function preservation is a growing concern in the surgical management of kidney tumors, particularly with the rise in chronic kidney disease worldwide. Recent surgical innovations have focused on modifying renorrhaphy techniques to minimize renal damage. Emerging evidence suggests that omitting cortical suturing may reduce operative time, blood loss, and renal parenchymal loss without increasing major complications. This randomized controlled trial aims to compare outcomes between medullary-only and combined cortical-medullary suture techniques during robot-assisted partial nephrectomy, with the goal of identifying the approach that best balances functional preservation and surgical safety.