OBJECTIVES: To better predict operative time using patient/surgical characteristics among men undergoing radical retropubic prostatectomy or robot-assisted laparoscopic prostatectomy in order to achieve more efficient operative scheduling and potentially decrease costs in the Veterans Health System. METHODS: We analyzed 2619 men treated with radical retropubic prostatectomy (n = 2005) or robot-assisted laparoscopic prostatectomy (n = 614) from 1993 to 2013 from six Veterans Affairs Hospitals in the Shared Equal Access Regional Cancer Hospital database. Age, body mass index, race, biopsy Gleason, prostate weight, undergoing a nerve-sparing procedure or lymph node dissection, and hospital surgical volume were analyzed in multivariable linear regression to identify predictors of operative time and to quantify the increase/decrease observed. RESULTS: In men undergoing radical retropubic prostatectomy, body mass index, black race, prostate weight and a lymph node dissection all predicted longer operative times (all P ≤ 0.004). In men undergoing robot-assisted laparoscopic prostatectomy, biopsy Gleason score and a lymph node dissection were associated with increased operative time (P ≤ 0.048). In both surgical methods, a lymph node dissection added 25-40 min to the operation. Also, in both, each additional operation per year per center predicted a 0.80-0.89-min decrease in operative time (P ≤ 0.001). CONCLUSIONS: Overall, several factors seem to be associated with quantifiable changes in operative time. If confirmed in future studies, these findings can allow for a more precise estimate of operative time, which could decrease the overall cost to the patient and hospital by aiding in operating room time management.