['In men with prostate cancer, pretreatment prostate-specific antigen (PSA) velocity (PSAV) has been demonstrated as a predictor of biochemical and survival outcomes in patients undergoing radical prostatectomy (RP). The utility of pretreatment PSAV in predicting outcomes after radiotherapy (RT), with or without androgen-deprivation therapy (ADT), is less certain. This study was undertaken to determine whether pretreatment PSAV is associated with biochemical disease-free survival, patterns of recurrence, and survival outcomes in men treated with radiation therapy and ADT.', 'Two hundred seventy-seven patients with intermediate- and high-risk prostate cancer treated with RT and ADT formed the study cohort. Kaplan-Meier survival estimates and Cox regression analyses were used to evaluate whether PSAV was associated with disease outcomes.', 'The median age of diagnosis was 70 years, and the median follow-up was 6.8 years. Men with a PSAV in the highest quartile tended to have higher risk disease at presentation (P = .028). After adjustment for known prognostic factors and duration of ADT, men who had a PSAV in the highest quartile had an increased risk of distant metastasis (hazard ratio [HR], 4.0; 95% confidence interval [95% CI], 1.61-9.9 [P = .003]) and prostate cancer-specific mortality (HR, 2.75; 95% CI, 1.27-5.95 [P = .01]) compared with men who had a lower PSAV, but had no increase in the risk of local recurrence (P = .76).'] Is pretreatment prostate-specific antigen velocity associated with development of distant metastases and prostate cancer mortality in men treated with radiotherapy and androgen-deprivation therapy?