Robot-assisted radical prostatectomy (RARP) and external beam radiotherapy (EBRT) are widely used treatment options for high-risk prostate cancer. To date, it is unclear which treatment for high-risk prostate cancer is superior in terms of health-related quality of life (HRQoL), functional outcomes, cost-effectiveness, progression-free survival (PFS) and distant metastasis-free survival (DMFS). In this health care evaluation, we aim to address this knowledge gap.