- Background: While much of the gender difference in the treatment of coronary artery disease (CAD) results from the fact that the women being treated are older and have more co-morbidities, it remains to be established whether a true gender bias exists. We compared physicians' attitudes and practice toward preventive therapy in men and women with CAD. Hypothesis: Physicians perceive the prevention of CAD in men as more important than in women. Methods: In the “attitude study,” we obtained data on the attitudes of 172 physicians toward treatment, using hypothetical case histories of 58-year-old male and postmenopausal female patients with identical clinical and laboratory data and mild coronary atherosclerosis on angiography. In the “actual practice study,” we evaluated the lipoprotein levels and prescription of lipid-lowering medications from medical records of 344 male and female patients with angiographic evidence of CAD. Results: In the hypothetical case histories, physicians in general considered the male patient to be at higher risk and prescribed aspirin (91 vs. 77%, p < 0.01) and lipid-lowering medications (67 vs. 54%, p < 0.07) more often for the male patient. Evaluation of medical charts of patients with CAD revealed that in patients with baseline low-density lipoprotein cholesterol > 110 mg/dl, 77% of the males received a lipid-lowering medication, compared with only 47% of the female patients (p < 0.001). Conclusions: We found evidence for a gender bias in the attitude as well as in actual practice of secondary prevention toward patients with CAD. While the proportion of male patients receiving lipid-lowering medications appears appropriate, the proportion of women receiving such treatment remains undesirable.