Objective There are known disparities in endometrial cancer survival with black women who experience a greater risk of death compared with white women. The purpose of this investigation was to evaluate the role of comorbid conditions as modifiers of endometrial cancer survival by race. Study Design Two hundred seventy-one black women and 356 white women who had been diagnosed with endometrial cancer from 1990-2005 were identified from a large urban integrated health center. A retrospective chart review was conducted to gather information on comorbid conditions and other known demographic and clinical predictors of survival. Results Black women experienced a higher hazard of death from any cause (hazard ratio HR 1.51; 95% confidence interval CI, 1.22–1.87) and from endometrial cancer (HR, 2.42; 95% CI, 1.63–3.60). After adjustment for known clinical prognostic factors and comorbid conditions, the hazard of death for black women was elevated but no longer statistically significant for overall survival (HR, 1.22; 95% CI, 0.94–1.57), and the hazard of death from endometrial cancer remained significantly increased (HR, 2.27; 95% CI, 1.39–3.68). Both black and white women with a history of hypertension experienced a lower hazard of death from endometrial cancer (HR, 0.47; 95% CI, 0.23–0.98; and HR, 0.35; 95% CI, 0.19–0.67, respectively). Conclusion The higher prevalence of comorbid conditions among black women does not explain fully the racial disparities that are seen in endometrial cancer survival. The association between hypertension and a lower hazard of death from endometrial cancer is intriguing, and further investigation into the underlying mechanism is needed.