Objective: To determine whether preoperative cystometry and a pressure flow study (PFS) are necessary in patients with end-stage renal disease from nonurologic causes who will undergo renal transplantation., Methods: From April 2009 to June 2010, 30 patients scheduled to undergo renal transplantation were prospectively evaluated with cystometry and PFS. The evaluation was performed immediately before and 6 months after renal transplantation. The inclusion criteria were age >18 years and end-stage renal disease secondary to nonurologic disease., Results: Improvement in the cystometry and PFS parameters was observed after the return of diuresis at 6 months after transplantation. The parameter changes from baseline to the 6-month evaluation were as follows: first sensation of bladder filling, 88.8-168.7 mL (P = .0005); first desire to void, 137.2-251.1 mL (P <.0001); maximal cystometric capacity, 221.2-428.7 mL (P <.0001); bladder compliance, 73.9-138.6 mL/cm H2O (P = .03); and maximal flow rate, 8.1-15.8 mL/s (P <.0001). The Abrams-Griffiths number in the men decreased from 31.8 to 15.2 (P = .002). No significant changes were observed in the detrusor pressure at the maximal flow rate or the postvoid residual urine volume. Patients with a 24-hour urine output <200 mL tended to have had significantly worse parameters before transplantation., Conclusion: Significant improvement in the cystometry and PFS parameters was observed in patients with end-stage renal disease, without urologic disease, 6 months after transplantation, and was associated with recovery of the glomerular filtration rate and urine output by the renal graft., (Copyright © 2014 Elsevier Inc. All rights reserved.)