The prevalence rates of hypertension among adult (ages 18-74) Mexican Americans, Cuban Americans, and Puerto Ricans were estimated using data from the 1982-84 Hispanic Health and Nutrition Examination Survey (HHANES). Hypertension is defined as diastolic greater than or equal to 90 mm Hg, or systolic greater than or equal to 140 mm Hg, or currently taking antihypertensive medication. Among Mexican Americans in the Southwestern United States, 16.8 percent of the males and 14.1 percent of the females were found to be hypertensive. Among Cuban Americans in Dade County, Florida 22.8 percent of the males and 15.5 percent of the females were hypertensive. Among Puerto Ricans in the New York City area 15.6 percent of the males and 11.5 percent of the females were hypertensive. The age-adjusted rates are significantly lower than comparable rates for Whites and Blacks as measured in the second National Health and Nutrition Examination Survey (NHANES II), 1976-80. Control of hypertension in the HHANES populations fall short of the 1990 Objectives for the Nation established by the US Public Health Service 60 percent (34 percent controlled Mexican American hypertensives, 27.8 percent controlled Cuban American hypertensives, and 29 percent controlled Puerto Rican hypertensives.