Background: This study examined the independent and incremental prognostic value of exercise thallium single-photon emission computed tomographic imaging in 212 women who also underwent coronary angiography. Methods and Results: The left ventricular ejection fraction was normal (65%±15%). During a mean follow-up of 40 months, 27 women had events (cardiac death or nonfatal myocardial infarction). Univariate Cox survival analysis showed several variables to be different between patients with events and those without events: age, exercise heart rate, the extent of coronary artery disease, reversible thallium defects, number of segments with reversible abnormality, and size of perfusion abnormality. Multivariate survival analysis showed that a large perfusion abnormality and age were the independent predictors of events. Actuarial life-table analysis showed that women with a large thallium abnormality (≥15% of the myocardium) had significantly worse event-free survival rates than had women with no or small abnormalities (Mantel-Cox statistic=16; p=0.0001). Conclusions: Thus exercise thallium-201 single-photon emission computed tomographic imaging provides independent and incremental prognostic information to clinical, exercise, and coronary angiographic results in women. The presence of a larger thallium abnormality identifies women at high risk of cardiac events. © 1995 American Society of Nuclear Cardiology.