This study examined whether currently employed women are at increased risk of coronary heart disease relative to full-time homemakers. Subjects were 1,041 Mexican-American and non-Hispanic white women aged 25-64 years, residing in households randomly selected from three socioculturally distinct neighborhoods in San Antonio, Texas. No statistically significant differences between employed women and homemakers were found for obesity, total serum cholesterol, low density lipoprotein cholesterol, systolic and diastolic blood pressures, or cigarette smoking. Highly significant differences favoring employed women over homemakers were found for both Mexican Americans and non-Hispanic whites in high density lipoprotein (HDL) cholesterol, ratio of HDL cholesterol to total cholesterol, and triglycerides. These differences were not explained by obesity, exercise, cigarette smoking, alcohol consumption, use of exogenous estrogens, and use of oral contraceptives, or by the healthy worker effect, and were observed at all occupational levels. Employed women ate a less atherogenic diet than full-time homemakers, but it is not clear that this nutritional factor could explain the differences in HDL cholesterol and triglycerides found in this study. The magnitude of the employment status difference in HDL cholesterol for both ethnic groups was in a range (3-4 mg/100 ml) associated with protection against coronary heart disease.