The serum levels of estradiol and testosterone as well as established risk factors for coronary heart disease were estimated in 61 men (mean age 70.0 +/- 6.4 [SD] years) with coronary heart disease and in 61 matched control subjects enrolled in the Framingham Heart Study. The mean serum estradiol level was significantly higher in the subjects with coronary disease (p = 0.011). This difference in estradiol level increased with the exclusion of subjects older than 75 years (p less than 0.001). The mean serum testosterone level was not significantly different. None of the established risk factors for coronary heart disease was different between subjects with coronary disease and control subjects except blood glucose level, which was higher in the subjects with coronary disease (p = 0.025). We conclude that hyperestrogenemia is an important correlate of coronary heart disease in men.