To compare perioperative, oncological and functional outcomes of laparoscopic radical prostatectomy (LRP) and robot-assisted laparoscopic radical prostatectomy (RALP) with emphasis on health-related quality of life (HRQOL) data as few studies exist. Patients underwent RALP or LRP by a single, fellowship trained surgeon with a standard clinical care pathway. HRQOL data using the Expanded Prostate Cancer Index Composite (EPIC) were collected at 0, 3, 6 and 12 months after 175 consecutive LRP and 174 RALP procedures. Urinary and sexual function outcomes were compared using two methods: (1) EPIC summary/subscale analyses described as percent return to baseline function and (2) traditional single-question analysis. The two groups were statistically similar with respect to demographics, clinical stage, perioperative outcomes, stage-specific surgical margin rates, and baseline urinary and sexual function scores. There was no statistical difference in postoperative urinary function between RALP and LRP using EPIC or single-question analyses at 3, 6 and 12 months. EPIC questionnaire data showed a greater return to baseline sexual function over time (mixed model analysis) in RALP than in LRP patients who had a bilateral nerve sparing procedure (Sexual Summary Score, P= 0.005; Sexual Function and Bother Subscales, P= 0.007). Using EPIC, RALP patients receiving a bilateral nerve sparing procedure showed improved percent return to baseline potency at 3 and 6 months (P < 0.025) compared with LRP patients, but had similar outcomes at 12 months (73.7% vs 66.2%, P= 0.3). Single-question analysis suggested improved potency after RALP compared with LRP, with a greater percentage of RALP patients reporting successful sexual intercourse in the past 4 weeks (87.5% vs 66.7% at 12 months, P= 0.06). When comparing surgical techniques, RALP and LRP groups showed statistically similar postoperative urinary function outcomes. RALP patients had an earlier return of sexual function when compared with LRP patients after a bilateral nerve sparing procedure. © 2011 THE AUTHORS. BJU INTERNATIONAL © 2011 BJU INTERNATIONAL.