To evaluate the impact of Retzius-sparing robot-assisted radical prostatectomy (posterior approach) on early recovery of urinary continence (UC) compared to the conventional approach (anterior approach) for the treatment of clinically localized prostate cancer (PCa). Methods A total of 110 consecutive patients with clinically localized PCa were prospectively randomized in a 1:1 ratio to an anterior group (n = 55) or a posterior group (n = 55). The primary outcome was immediate UC, defined as freedom from any pad use within 1 week after removal of the urinary catheter. The UC rate following surgery was also calculated with Kaplan-Meier curves, and the log-rank test was used for statistical comparison. Intra-operative outcomes, pathological data and oncological outcomes, including positive surgical margin (PSM) status and biochemical recurrence-free survival (BCRFS), were also compared between the two groups. The comparison of the two approaches was also analysed in subgroups after risk stratification. Results Of the patients who underwent the posterior approach, 69.1% achieved immediate UC compared with 30.9% in the anterior group (relative risk 2.24, 95% confidence interval [CI] 1.48-3.51; P = 0.000). The relative Kaplan-Meier curves for UC during the 12-month follow-up revealed statistically better recovery in the posterior group when compared with the anterior group (hazard ratio [HR] 1.51, 95% CI 1.01-2.24; log-rank P = 0.007). No statistically significant differences were observed between the groups regarding complications (P = 0.399), PSM status (P = 0.225) or BCRFS (HR 4.80, 95% CI 0.97-23.78; log-rank P = 0.111). In sub-analyses, no significant difference between the two approaches with regard to UC recovery in patients with high-risk PCa was observed (HR 1.26, 95% CI 0.63-2.51; log-rank P = 0.415). Conclusions The Retzius-sparing approach significantly improved early recovery of UC compared to the conventional approach. Further prospective studies are needed to confirm the benefits of the Retzius-sparing approach for clinically localized PCa, especially for high-risk cases.