Résumé : We prospectively compared, within the same center and during the same period of time, the perioperative parameters as well as the oncological and functional results of both open retropubic (ORP) and laparoscopic radical prostatectomy (LRP). From September 1999 to September 2001, 162 patients with prostate cancer were treated with radical prostatectomy, 77 using an open retropubic technique, and 85 by the laparoscopic extraperitoneal approach. We prospectively recorded pre-, per- and postoperative parameters and complications, and evaluated the carcinological and functional results, comparing both approaches. There were no significant differences in the preoperative characteristics of the two groups. Mean operative time was statistically longer with LRP than with ORP (288 vs 168 min, P<0.0001) but median blood loss was decreased (400 vs 1,300 ml, P<0.0001). Major complications occurred in a similar number of cases (5% vs 2.4%, NS) while minor complications occurred more frequently with ORP (24.6 vs 11.8%, P=0.003). Pathological examination revealed a similar distribution of Gleason scores and stages in each group. Positive surgical margins in pT2 cases occurred in 7.8% of LRP and 7.3% of ORP. Continence rates (no pad and no leakage at all) were similar (83.9% in ORP vs 80.7% in LRP, NS). Potency rates were similar after 1 year in patients undergoing bilateral nerve sparing (55% in ORP vs 65% in LRP, NS). However, patients operated by LRP had more spontaneous erections. We conclude that this prospective, comparative study shows that LRP, when performed in specialized centers, gives oncological and functional results comparable to open surgery.