© 2017 American Medical Association. IMPORTANCE Elevated systolic blood (SBP) pressure is a leading global health risk. Quantifying the levels of SBP is important to guide prevention policies and interventions. OBJECTIVE To estimate the association between SBP of at least 110 to 115mmHg and SBP of 140mmHg or higher and the burden of different causes of death and disability by age and sex for 195 countries and territories, 1990-2015. DESIGN A comparative risk assessment of health loss related to SBP. Estimated distribution of SBP was based on 844 studies from 154 countries (published 1980-2015) of 8.69 million participants. Spatiotemporal Gaussian process regression was used to generate estimates of mean SBP and adjusted variance for each age, sex, country, and year. Diseases with sufficient evidence for a causal relationship with high SBP (eg, ischemic heart disease, ischemic stroke, and hemorrhagic stroke) were included in the primary analysis. MAIN OUTCOMES AND MEASURES Mean SBP level, cause-specific deaths, and health burden related to SBP (≤110-115mmHg and also≤140mmHg) by age, sex, country, and year. RESULTS Between 1990-2015, the rate of SBP of at least 110 to 115mmHg increased from 73 119 (95%uncertainty interval [UI], 67 949-78 241) to 81 373 (95%UI, 76 814-85 770) per 100000, and SBP of 140mmHg or higher increased from 17 307 (95%UI, 17 117-17 492) to 20526 (95%UI, 20283-20746) per 100000. The estimated annual death rate per 100000associated with SBP of at least 110 to 115mmHg increased from 135.6 (95%UI, 122.4-148.1) to 145.2 (95%UI 130.3-159.9) and the rate for SBP of 140mmHg or higher increased from 97.9 (95%UI, 87.5-108.1) to 106.3 (95%UI, 94.6-118.1). Loss of disability-adjusted life-years (DALYs) associated with SBP of at least 110 to 115mmHg increased from 148 million (95%UI, 134-162 million) to 211 million (95% UI, 193-231 million), and for SBP of 140mmHg or higher, the loss increased from 95.9 million (95%UI, 87.0-104.9 million) to 143.0million (95%UI, 130.2-157.0million). The largest numbers of SBP-related deathswere caused by ischemic heart disease (4.9 million [95%UI, 4.0-5.7 million]; 54.5%), hemorrhagic stroke (2.0million [95%UI, 1.6-2.3 million]; 58.3%), and ischemic stroke (1.5 million [95%UI, 1.2-1.8 million]; 50.0%). In 2015, China, India, Russia, Indonesia, and the United States accounted for more than half of the globalDALYs related to SBP of at least 110 to 115mmHg. CONCLUSIONS AND RELEVANCE In international surveys, although there is uncertainty in some estimates, the rate of elevated SBP (≤110-115 and≤140mmHg) increased substantially between 1990 and 2015, and DALYs and deaths associated with elevated SBP also increased. Projections based on this sample suggest that in 2015, an estimated 3.5 billion adults had SBP of at least 110 to 115mmHg and 874 million adults had SBP of 140mmHg or higher.