This study evaluated the effect of gender on left ventricular (LV) function in 84 men and 20 women with coronary artery disease (CAD) (greater than or equal to 50% luminal narrowing of one or more of the major coronary arteries). All patients underwent rest and upright exercise radionuclide ventriculography on a bicycle ergometer. There were no differences between men and women in age, hypertension, medications, and extent of CAD disease (number of diseased vessels or CAD score). Although men exercised for a longer duration than women, both achieved similar exercise heart rates and blood pressures. Angina pectoris or ST depression during exercise occurred in similar proportion in both groups. The LV ejection fraction and the systolic pressure-to-end-systolic volume ratio at rest and during exercise were similar in both men and women. Thus, men and women with comparable extent of CAD demonstrate similar manifestations of myocardial ischemia and LV dysfunction during exercise. Gender does not appear to influence LV function independent of the extent of CAD.