Since 1960, data have been collected on measured blood pressure for non-Hispanic whites and blacks. However, few data have been available measured blood pressure for Mexican Americans (1). Until the release of data from the National Health and Nutrition Examination III, Phase I (NHANES III), the only source of blood pressure data for most of the Mexican American population in the United States was the Hispanic Health and Nutrition Examination Survey (HHANES). Data on measured blood pressure for other Hispanic subgroups (i.e., Cuban Americans and Puerto Ricans) were available in HHANES but not in NHANES III. To identify trends in prevalence, awareness, treatment, and control of hypertension among Mexican Americans aged 18-74 years, HHANES (conducted during 1982-1984) and NHANES III (conducted during 1988-1991) were analyzed. This report summarizes the results of that analysis.