The observation that Hispanics have lower all-cause and cardiovascular mortality rates despite increased rates of diabetes and obesity and lower socioeconomic status has been termed the "Hispanic paradox." The authors therefore examined the relation between ethnicity and mortality in 1,438 Mexican-American and 921 non-Hispanic White San Antonio Heart Study participants, aged 45-64 years when they enrolled between 1979 and 1988. Over an average of 14.5 years, 466 deaths occurred: 238 attributed to cardiovascular disease (death certificate International Classification of Diseases, Ninth Revision, codes 401-414 or codes 420-447 with the exception of code 427.5) and 117 attributed to coronary heart disease (codes 410-414). Age- and gender-adjusted hazard ratios for all-cause, cardiovascular, and coronary heart disease mortality comparing Mexican Americans with non-Hispanic Whites were 1.50 (95% confidence interval (CI): 1.23, 1.81), 1.70 (95% CI: 1.30, 2.24), and 1.60 (95% CI: 1.09, 2.36), respectively. After adjusting for possible confounders, among diabetic individuals not using insulin, the authors found excess risk of all-cause, cardiovascular, and coronary heart disease mortality associated with being Mexican American; however, in nondiabetic individuals and insulin-using diabetic individuals, Mexican Americans and non-Hispanic Whites appeared to be at similar risk of mortality. Contrary to the prediction of the "Hispanic paradox," in the San Antonio Heart Study, Mexican Americans were at greater risk of all-cause, cardiovascular, and coronary heart disease mortality than were non-Hispanic Whites.