Retzius-sparing robot-assisted radical prostatectomy (RS-RARP) allows the preservation of the structures advocated to play a crucial role in the continence mechanism. This study aims to evaluate the association between adjuvant radiation therapy (aRT) and urinary continence (UC) recovery after RS-RARP. For the purpose of the current study, all patients submitted to RS-RARP for prostate cancer (PCa) at a single high-volume European institution between January 2010 and December 2021 were identified. Only patients that harbored pT2 stage with positive surgical margins or pT3/pN1 stage with or without positive surgical margins were included in the analyses. Two groups of patients were identified as follows: patients who had undergone aRT and patients submitted to observation (no-aRT patients). As per definition, aRT was delivered within 1–6 months after surgery. After 1:1 propensity score matching, 124 aRT patients were compared with 124 no-aRT patients who continued standard follow-up protocol after surgery. UC recovery was 81 vs. 84% in aRT vs. no-aRT patients (p = 0.7). In multivariable Cox regression analyses, aRT did not reach the independent predictor status for UC recovery at 12 months. In the subgroup analysis including only aRT patients, only the nerve-sparing technique was independently associated with UC recovery at 12 months. Conversely, the type of aRT (IMRT/VMAT vs. 3D-CRT) did not reach the independent predictor status for UC recovery at 12 months. The current study is the first to address the association between aRT and UC recovery in patients treated with RS-RARP for PCa. Based on our data, aRT is not associated with worse UC recovery. In the cohort of patients treated with aRT, the nerve-sparing technique independently predicted UC recovery.