Background: Patients (pts) with prostate cancer treated with prolonged androgen deprivation therapy (ADT) will eventually develop castration-resistant disease. Treatment of pts with nmCRPC with darolutamide (DARO) delays the development of metastases, which are associated with cancer-related morbidity. DARO is a structurally unique oral androgen receptor inhibitor approved by the FDA for the treatment of nmCRPC, based on prolonged metastasis-free survival (MFS) compared with placebo (median 40.4 months vs.18.4 months, respectively) in the ARAMIS phase III clinical trial. DARO showed a similar incidence of adverse events (AEs) compared to ADT alone and has a low potential for drug-drug interactions. However, phase III clinical trials cannot fully reflect all the facets of real-world pts. Therefore, non-interventional studies in the real-world setting, such as DAROL, are able to provide additional insight into the patterns of use and real-world safety profile of recently approved drugs. Methods: (NCT04122976) will enrol participants in the US, Brazil, Japan, and the EU. Eligible pts include men with histologically confirmed nmCRPC aged ≥18 yrs, life expectancy ≥3 months, and initiated on DARO treatment as per investigators’ decision within 3 days prior to enrollment. DAROL opened for enrollment in December 2019 in the US with a projected enrollment of 1000 pts. The primary endpoint of DAROL is safety. Treatment-emergent AEs will be collected during the study. Secondary endpoints to measure clinical effectiveness are MFS, time to symptomatic skeletal event, time to prostate-specific antigen progression, survival rate, and duration of DARO therapy. Other endpoints include pt demographics and characteristics, and prior and subsequent therapy. The estimated primary completion date is December 30, 2024. Clinical trial information: NCT04122976.