Some authors reported that adopting a nerve sparing technique during radical cystoprostatectomy improves the continence outcome of orthotopic diversion in patients with invasive bladder carcinoma. We urodynamically evaluated the effect of nerve sparing cystoprostatectomy on external urethral sphincteric function. A total of 30 consecutive male patients who underwent nerve sparing cystoprostatectomy and ileal neobladder (NS group) were compared to a control group of 30 patients who underwent a similar procedure but without nerve sparing (non-NS group). Continence status was thoroughly clinically evaluated in parallel to erectile function in both groups. The urethral sphincteric mechanism was evaluated with urethral pressure profilometry in different positions. Better urethral pressure profile parameters were found in patients in the NS group. Significantly longer functional urethral length (34.8 mm) was detected in NS group than in the non-NS group (30.1 mm). Moreover, the maximum urethral pressure was higher in the NS group but not to a statistically significant level. In the NS group there were no statistically significant differences between potent and impotent subgroups regarding the continence rate or urethral pressure parameters. There is urodynamic evidence that the nerve sparing technique improved urethral sphincteric function and, consequently, the continence rate. The denervated, most proximal part of the urethra in non-NS cases with lack of contraction and, therefore, any pressure, is a possible explanation for the difference in UPP.