This study aimed to assess the surgical outcomes of single-layer versus double-layer renorrhaphy in robot-assisted laparoscopic partial nephrectomy (RAPN) performed by an experienced surgeon.We enrolled 655 patients who underwent RAPN between January 2019 and June 2023. After excluding those with multiple tumors or incomplete medical records, 554 patients were included in the final analysis. We compared surgical outcomes between single-layer renorrhaphy (outer cortical closure) and double-layer renorrhaphy (inner layer suture and outer cortical closure), adjusting for preoperative factors such as sex, age, body mass index, American Society of Anesthesiologists score, preoperative estimated glomerular filtration rate (eGFR), preoperative complications (diabetes or hypertension), surgical approach (transperitoneal or retroperitoneal), tumor size, and tumor complexity, using propensity score matching. Of the 554 patients analyzed, 59 were classified into the single-layer group and 495 into the double-layer group. Before matching, the double-layer group had more complex and larger tumors. After matching, 58 patients were included in each group. The single-layer group showed significantly shorter operative times (91 min vs. 100 min, p = 0.0361), lower estimated blood loss (EBL) (7.9 ml vs. 27 ml, p = 0.021), and better preservation of eGFR (− 1.2% vs. − 5.1%, p = 0.0313). Other outcomes, such as perioperative complications and postoperative hospital stay, were not significantly different between the groups. Single-layer renorrhaphy demonstrated better surgical outcomes, including shorter operative time, lower EBL, and better preservation of kidney function, compared to double-layer renorrhaphy. These findings suggest that single-layer reconstruction may optimize RAPN outcomes in selected patients.