The authors ascertained cardiovascular events (myocardial infarction and angina pectoris) in 498 women with systemic lupus erythematosus seen at the University of Pittsburgh Medical Center from 1980 to 1993 (3,522 person-years). Subjects were stratified by age, and cardiovascular event incidence rates were determined. The authors compared these rates with cardiovascular event rates were determined. The authors compared these rates with cardiovascular event rates occurring over the same time period in 2,208 women of similar age participating in the Framingham Offspring Study (17,519 person-years). Age-specific rate ratios were computed to determine whether the cardiovascular events in the lupus cohort were greater than expected. The risk factors associated with cardiovascular events in women with lupus were determined. There were 33 first events (11 myocardial infarction, 10 angina pectoris, and 12 both angina pectoris and myocardial infarction) after the diagnosis of lupus: two thirds were under the age of 55 years at the time of event. Women with lupus in the 35- to 44-year age group were over 50 times more likely to have a myocardial infarction than were women of similar age in the Framingham Offspring Study (rate ratio = 52.43, 95% confidence interval 21.6-98.5). Older age at lupus diagnosis, longer lupus disease duration, longer duration of corticosteroid use, hypercholesterolemia, and postmenopausal status were more common in the women with lupus who had a cardiovascular event than in those who did not have an event. Premature cardiovascular disease is much more common in young premenopausal women with lupus than in a population sample. With the increased life expectancy of lupus patients due to improved therapy, cardiovascular disease has emerged as a significant threat to the health of these women. The impact of this problem has been underrecognized, with little focus placed on aggressive management of hypercholesterolemia and other possible risk factors.