Objectives Although laparoscopic radical prostatectomy (LRP) is accomplished within 2 to 3 hours by experienced surgeons, less is known about the operating times (OTs) for recently trained surgeons or the influence of additional factors. As of November 2001 at our institution, two senior surgeons had each performed more than 100 cases of LRP and two junior surgeons had each performed fewer than 30. We prospectively studied the next 100 consecutive LRPs to assess the factors influencing the OT. Methods Transperitoneal LRPs were performed by two senior (n = 62) and two junior surgeons (n = 38) with random case assignment. We assessed body mass index, prostate size, prior abdominal surgery, androgen deprivation, surgeon experience, procedures in addition to LRP, lymph node dissection, nerve sparing, and sural nerve grafting as potential predictors of the OT. Results Prostate weight, androgen deprivation, and prior abdominal surgery did not significantly affect the OT, but grade 1 obesity increased the OT by an average of 38 minutes. The mean OT by surgeon experience was 214 minutes for seniors and 347 minutes for juniors ( P <0.001). By procedure type, the OT ranged from 180 minutes for LRP only by seniors to 459 minutes for LRP plus lymph node dissection plus sural nerve grafting by juniors. Lymph node dissection and sural nerve grafting significantly increased the OT by 46 and 101 minutes, respectively, and nerve sparing did not. For each combination of procedures, seniors averaged significantly shorter times than did juniors. A multiple regression model with stepwise selection showed that prostate weight, sural nerve grafting, pelvic lymph node dissection, use of a surgical robot, and surgeon experience significantly affected the OT. Conclusions The results of this prospective study of 100 cases of LRP showed that the OT for senior surgeons averaged 2 to 3 hours, but less experienced surgeons, and additional procedures, add significantly to the OT.