Objectives: The preservation of the bladder neck in radical prostatectomy has been supported in literature as an important step in the urinary continence maintenance. In this prospective study a comparison was made of the urinary continence rates and neoplasm control based on preservation or resection of the bladder neck. Material and Methods: Patients with stage T1c - T2c prostate adenocarcinoma treated by radical prostatectomy, were randomized during the surgery, by drawing, either for the bladder neck preservation or for resection. The continence was evaluated in an interview 2 days after the Foley catheter removal and in the second and sixth months after the surgery. The same pathologist examined the surgical margins systematically. The neoplasm control was assessed by prostate specific antigen (PSA) dosage in the second month after the surgery and later, semiannually. Results: An interim analysis of the first 70 patients, showed a high incidence of exclusively involvement of the bladder neck surgical margin in the preservation group and, due to this finding, the study was closed prematurely. Each group was assigned 35 patients but the bladder neck could not be preserved in 4 and 1 died, leaving 31 in the preservation group and 38 in the resection group. There was no statistical difference between the 2 groups as to the early or late urinary incontinence rates. Two days after the catheter removal and in the second and sixth months after the surgery the respective rates were: 21%, 13% e 5% in the bladder neck resection group and 32%, 13% e 3% in the bladder neck preservation group. The PSA dosage showed a biochemical recurrence of the neoplasm (> 0.3 ng/ml) in six of the 30 (20%) patients submitted to bladder neck preservation and in five of the 33 (15.15%) patients submitted to bladder neck resection, after a median of 27 months of follow-up (25 to 30 months). The difference between the two groups was not statistically significant (p = 0.74). Conclusions: The bladder neck preservation in radical prostatectomy does not improve the postoperative continence rates, shows a tendency to produce more positive surgical margins at the bladder neck level, but the neoplasm evolution is not different when compared to patients submitted to bladder neck resection.