Mortality following myocardial infarction (MI) is greater among women than men and among Mexican Americans than non-Hispanic whites. Because therapy can affect mortality following MI, we examined differences in discharge therapy among these groups. Data regarding discharge therapy of 982 patients in the Corpus Christi Heart Project showed that women received fewer cardiovascular drugs than men, and Mexican Americans received fewer cardiovascular drugs than non-Hispanic whites. In multivariate analysis adjusting for age, cigarettes smoking, diabetes, hypertension, congestive heart failure, and serum cholesterol, the odds ratio for receipt of cardiovascular medications was 0.51 (95% CI: 0.28-0.93) for women versus men and 0.62 (0.3-1.15) for Mexican Americans versus non-Hispanic whites. Beta-blockers were prescribed rarely. Thus, treatment differences between ethnic and gender groups were observed following MI. Further research is needed to determine both the reasons for these differences and the extent to which these differences contribute to the observed survival patterns following MI.