Background: To report health-related quality of life outcomes as assessed by validated patient-reported outcome measures (PROMs) after radical prostatectomy (RP). Methods: This study analyzed patients treated with RP within The PROState cancer monitoring in Italy, from the National Research Council (Pros-IT CNR). Italian versions of Short-Form Heath Survey and university of California los Angeles-prostate cancer index questionnaires were administered. PROMs were physical composite scores, mental composite scores and urinary, bowel, sexual functions and bothers (UF/B, BF/B, SF/B). Baseline unbalances were controlled with propensity scores and stabilized inverse weights; differences in PROMs between different RP approaches were estimated by mixed models. Results: Of 541 patients treated with RP, 115 (21%) received open RP (ORP), 90 (17%) laparoscopic RP (LRP) and 336 (61%) robot-assisted RP (RARP). At head-to-head comparisons, RARP showed higher 12-month UF vs. LRP (interaction treatment * time p = 0.03) and 6-month SF vs. ORP (p < 0.001). At 12-month from surgery, 67, 73 and 79% of patients used no pad for urinary loss in ORP, LRP and RARP respectively (no differences for each comparison). Conversely, 16, 27 and 40% of patients declared erections firm enough for sexual intercourse in ORP, LRP and RARP respectively (only significant difference for ORP vs. RARP, p = 0.0004). Conclusions: Different RP approaches lead to significant variations in urinary and sexual PROMs, with a general trend in favour of RARP. However, their clinical significance seems limited.