Background: Heart failure and dementia are diseases of the elderly that result in billions of dollars in annual health care expenditure. With the aging of the United States population and increasing evidence of shared risk factors, there is a need to understand the conditions' shared contributions to nationwide mortality. The objectives of this study were to estimate the burden of mortality from heart failure and dementia and characterize the demographics of affected individuals., Methods and Results: This retrospective study used National Vital Statistics Data from 1999 to 2016 provided by the Centers for Disease Control and International Classification of Diseases (10th edition) codes for heart failure and dementia as defined by the Medicare Chronic Conditions Data Warehouse. From 1999 to 2016, deaths contributed to by both heart failure and dementia totaled 214,706 and constituted 4.00% of all heart failure deaths and 9.04% of all dementia deaths. Women were more affected than men, with higher age-adjusted mortality rates (per 1,000,000 person-years): 38.67 (95% confidence interval [CI] 38.47-38.87) versus 32.90 (95% CI 32.65-33.15; P < .001). Whites were affected more than blacks, with age-adjusted mortality rates (per 1,000,000 person-years) of 38.00 (95% CI 37.83-38.16) versus 31.06 (95% CI 30.54-31.59; P < .001). However, under the age of 65 years, higher crude mortality rates (per 1,000,000 person-years) were reported in men (0.20, 95% CI 0.18-0.22) compared with women (0.15, 95% CI 0.13-0.16; P < .001)., Conclusions: This study provides insight into temporal trends and nationwide mortality rates reported for heart failure and dementia. Our results suggest a disproportionate burden on populations over 85 years of age, whites, and women., (Copyright © 2018 Elsevier Inc. All rights reserved.)