Context: Because androgens are obligatory precursors of estrogens, it is reasonable to assume that their serum concentrations would exhibit positive correlations. If so, then epidemiologic studies that examine the association between androgens and pathological processes should adjust the results for the independent effect of estrogens. Objective: The objective of the study was to examine the interrelationships among testosterone (T), and rostenedione, estradiol (E2), estrone, and SHBG in postmenopausal women. Design: This was a cross-sectional study of women participating in the National Heart, Blood, and Lung Institute-sponsored Women's Ischemia Syndrome Evaluation study. Setting: The study was conducted at four academic medical centers. Patients: A total of 284 postmenopausal women with chest pain symptoms or suspected myocardial ischemia. Main Outcome Measures: Post hoc analysis of the relationships among sex steroid hormones with insulin resistance, body mass index (BMI), and presence or absence of coronary artery disease as determined by coronary angiography. Results: BMI was significantly associated with insulin resistance, total E2, free E2, bioavailable E2, and free T. Highly significant correlations were found for total T, free T, and androstenedione with total E2, free E2, bioavailable E2, and estrone and persisted after adjustment for BMI and insulin resistance. A significant relationship was present between total and free T and the presence of coronary artery disease after adjustment for the effect of E2. Conclusions: Serum levels of androgens and estrogens track closely in postmenopausal women referred for coronary angiography for suspected myocardial ischemia. Epidemiological studies that relate sex steroid hormones to physiological or pathological processes need to control for the independent effect of both estrogens and androgens. Copyright © 2008 by The Endocrine Society.