Background: The incidence of non-localized prostate cancer in the US has been increasing since 2011. While the etiology of this increase is unknown, improved detection of metastatic disease and changes in prostate-specific antigen (PSA) screening may be contributing factors. In this retrospective study, we report the frequency and characteristics of veterans with de novo metastatic prostate cancer to understand changes in the diagnosis over time. Methods: The study population consisted of veterans diagnosed with de novo metastatic Hormone Sensitive Prostate Cancer (mHSPC) with a biopsy between 2002 and 2021 in the Veterans Health Affairs Prostate Cancer Data Core were included. All patients had no prior diagnosis of prostate cancer and were classified as SEER stage ‘distant’. We collected the highest PSA within 3 months of diagnosis, age, race, and calculated the Charlson Comorbidity Index. Year of diagnosis was categorized into 5-year periods and differences over tine were assessed by chi-square linear by linear ANOVA test for linearity as appropriate. Results: 15,485 patients were diagnosed with de novo mHSPC between 2002 and 2021. The mean age was 72.9 years and the median PSA was 88.0 ng/mL. There was a 39% increase of the number of patients diagnosed with mHSPC (from 3,274 between 2002-2006 to 4,560 between 2017-2021). Mean age increased from 71.6 years between 2002-2006 to 74.4 between 2017-2021 (p < 0.001). Median PSA decreased from 96.6 ng/mL in 2002-2006 to 80.3 ng/mL in 2006-2021 (p < 0.001). The percentage of patients who were identified as black decreased from 29.8% between 2002-2006 to 25.4% between 2017 and 2021 (p < 0.001). Mean comorbidity index increased from 3.2 between 2002-2006 to 4.5 between 2017-2021 (p < 0.001). BMI increased from 26.2 between 2002-2006 to 27.2 between 2017-2021 (p < 0.001). Median overall survival improved from 26.7 months in 2002-2006 to 31.7 months in 2016-2021 (p < 0.001). Conclusions: Over a 20-year period, the Veterans diagnosed with prostate cancer were older, with higher comorbidities and with decreased PSA at diagnosis. Additionally, overall survival improved from 26.7 to 31.7 months. The findings of this study are consistent with a reduction in screening and more sensitive imaging modalities to detect metastatic disease combined with changes in the veteran population and improvements in treatment of mHSPC. Further study is warranted to understand these trends over the same time period.