['Pneumoperitoneum with an intra-abdominal pressure (IAP) of 14 mmHg is known to decrease renal function. Robotic-assisted radical prostatectomy (RARP) requires an IAP of more than 15 mmHg for operation. Therefore, we retrospectively investigated whether patients who underwent RARP experienced renal insufficiency during the postoperative period (at postoperative days 7 and 30).', 'One hundred patients who underwent RARP were enrolled in this study. Preoperative serum blood urea nitrogen (BUN) and serum creatinine (Cr) levels were measured. Creatinine clearance (CrCl) was calculated using the Cockcroft and Gault formula. CrCl was calculated at 1 day before surgery (baseline), 2 hr postoperatively, and at 1, 3, 7, and 30 days postoperatively (POD 1, POD 3, POP 7, and POD 30). Patients were assigned to abnormal CrCl (n = 52) or normal CrCl groups (n = 48) on the basis of these measurements.', 'Significant inter-group differences in BUN, Cr, and CrCl were observed at all postoperative time points. BUN and Cr decreased significantly at postoperative 2 hr and POD 1, 3, and 7 versus baseline in both groups, whereas CrCl increased significantly at postoperative 2 hr and POD 1, 3, and 7 versus baseline in both groups. However, BUN, Cr, and CrCl were similar at POD 30 and preoperatively in the two groups.'] Is postoperative renal function in patients unaltered after robotic-assisted radical prostatectomy?