300 Background: In patients with biochemically recurrent (BCR) nonmetastatic castration-sensitive prostate cancer (nmCSPC), guidelines support the use of clinical factors such as prostate-specific antigen doubling time (PSADT) and Gleason score to identify high-risk patients who are more likely to develop metastases and could benefit from earlier intervention. The current study aimed to understand criteria used by physicians in the real-world to categorize patients with BCR nmCSPC as high-risk. Methods: This analysis used data from the Adelphi Real World nmCSPC retrospective survey, completed by urologists and radiation oncologists in the US. Physicians extracted data from medical charts for their last 6–8 patients diagnosed with high-risk BCR nmCSPC since January 2021 (until July 2023). A physician attitudinal survey was also completed. Data were analyzed descriptively. Results: Overall, 84 physicians provided data (68 urologists; 16 radiation oncologists). When asked in general (not patient specific) to name clinical factors used to determine level of risk, physicians cited using multiple factors, most frequently PSADT (93%), Gleason score (88%), absolute PSA rise following definitive therapy (86%), and clinical stage (85%). PSADT was cited as the single most important clinical factor by nearly 50%, followed by Gleason score, clinical stage, and absolute PSA rise following definitive therapy (Table). For physicians who used PSADT to risk stratify, the median (IQR) threshold for high-risk was 6 (6–9) months. Aggregated patient-level data were analyzed for 352 patients with high-risk BCR nmCSPC, as defined by the physicians. Clinical factors used to classify patients as having high-risk BCR in this study included PSADT (58%), Gleason score (44%), absolute PSA rise after definitive therapy (42%), clinical stage (21%), and pathological findings at radical prostatectomy (15%). Overall, 65% of patients had a PSADT ≤9 months after BCR, and 68% had a PSADT < 12 months (high-risk per the AUA guidelines). Conclusions: Physicians reported using multiple clinical factors to classify patients as having high-risk BCR nmCSPC, with PSADT considered the most important for risk stratification. Appropriate and timely identification of patients as high-risk may help to identify patients for whom earlier intervention could be beneficial.[Table: see text]