Background: Advances in treatment for metastatic prostate cancer (mPC) have improved overall survival (OS) in clinical trials for mPC over the last 20 years. It is unclear whether these changes from trials have translated to improvements in survival in the real world. We sought to characterize trends in OS among patients with newly diagnosed mPC in two large national registries. Methods: Patients diagnosed from 2000-2019 were included. Patients from SEER-17 were included if stage at diagnosis was distant. For years prior to 2004, SEER Historic Stage A was used. Patients in the Veterans Affairs Prostate Cancer data core (VA) were included if the SEER summary stage variable was distant in the first record of prostate cancer in VA or oncology registry data for veterans diagnosed after 2018. Results: 55,661 patients were identified in SEER and 14,904 patients were identified in VA. Median age at presentation was 72 years in both datasets, with 16.6% identified as Black in SEER and 28.5% Black in VA. Median OS from 2000-2004 to 2015-2019 in SEER increased from 25 to 31 months, corresponding to a hazard ratio (HR) of 0.82 (p <0.001); median OS in VA increased from 25.8 to 30.9 months, corresponding to a HR of 0.912 (p=0.003). Patients <70 years of age had median OS that increased from 31 to 41 months (HR 0.78, p <0.001) in SEER and 34.4 to 42.2 months (HR 0.87, p=0.003) in VA compared to patients 70+ in SEER (21 to 26 months, HR=0.84, p<0.001) and in VA (21.6 to 25.6 months, HR=0.935, p=0.03). In SEER, black patients had worse survival compared to white patients (HR 1.10, p<0.001). Survival improvement over time in SEER was seen for both black (HR 0.81, p<0.001) and white (HR 0.83, p<0.001) patients. In VA, black patients had better OS compared to white patients (HR 0.96, p=0.0475). Survival improvement over time in VA was seen in black (HR 0.84, p<0.001), but was not significant in white (HR 0.94, p=0.052) patients. Conclusions: This real-world analysis demonstrates that median OS in de novo mPC has improved over the last 20 years, particularly in patients <70 years of age. However, these improvements are less than what has been observed in clinical trials. Black patients had inferior OS in SEER compared to white patients but in the VA black patients had better OS and an improvement in OS over time, potentially reflecting more equal access to care in the VA system.