To determine whether marital status combined with race serve as prognostic factors for survival in localized prostate cancer.Patients with localized prostate cancer were retrospectively extracted from the Surveillance, Epidemiology, and End Results (SEER) database. Chi-square test was used to investigate the association between marital status combined with race and other variables. Gray's test was used to compare the cumulative incidence function of different variables. Multivariable analysis was conducted to assess prognostic factors after adjusting for other variables.A total of 207,219 patients with localized prostate cancer from the SEER database from 2010 to 2016 were eligible. We found that black or single patients had the highest risk of mortality (p < 0.001). When marital status and race were combined, single black patients had the worst prognosis after adjusting for other variables (hazard ratio = 1.93, 95% confidence interval: 1.58-2.35; p < 0.001). Married status had a prognostic advantage in all races. In the same marital groups, whites and Asians had lower risk of prostate cancer-specific mortality and other-cause mortality than blacks with married and single status (p < 0.001).Marital status and race serve as prognostic factors for localized prostate cancer. Blacks or single individuals had higher risk of mortality when considered independently, and single black patients had the worst prognosis. Furthermore, married status was an advantage in the same race group, and whites and Asians had lower risk than blacks with married and single status. Accordingly, the interaction between race and marital status on prostate cancer prognosis in clinical practice should be assessed carefully.