What is already known about this topic? Approximately one third of U.S. adults have hypertension, and only about half of these adults have their hypertension under control. Hypertension is an important and common risk factor for heart disease and stroke, two of the leading causes of death in adults. What is added by this report? The examination component of National Health and Nutrition Examination Survey (NHANES) allows estimation of the prevalence of both diagnosed and undiagnosed hypertension, as well as awareness, treatment, and control of hypertension in Los Angeles County. During 2007–2014 the age-adjusted prevalence of hypertension among adults was significantly lower in Los Angeles County (23.1%) than in the United States (29.6%). Among adults with hypertension in Los Angeles County, awareness, treatment, and control improved significantly from 1999–2006 to 2007–2014; however, more than half of these adults still did not have their hypertension under control. What are the implications for public health practice? NHANES will continue to be an important source of data for monitoring progress in hypertension prevalence, awareness, treatment, and control, as evidence-based practices, such as those promoted through the Million Hearts initiative, continue to be implemented in Los Angeles County. © 2017 Department of Health and Human Services, All rights reserved.