Abstract The presence of ST-T-wave abnormalities in the resting electrocardiogram was reported as a predictor of coronary artery disease (CAD) and increased morbidity and mortality. However, the independent value of ST-T abnormalities for predicting the presence and severity of perfusion abnormalities during stress testing has not been studied in a homogenous patient group without known CAD. We evaluated the relation between resting ST-T abnormalities and myocardial perfusion abnormalities in 246 patients (age 59 ± 13 years, 114 men and 132 women) without known CAD or previous myocardial infarction referred for evaluation of possible myocardial ischemia by dobutamine (up to 40 μg/kg/min) stress sestamibi or tetrofosmin single-photon emission computed tomographic imaging. Resting ST-T abnormalities were present in 123 patients, whereas 123 patients with normal resting electrocardiograms served as a matched control group. Abnormal myocardial perfusion (fixed or reversible perfusion defects) was detected in 72% of men with and in 35% of men without resting ST-T abnormalities (p <0.0001), whereas the prevalence of myocardial perfusion abnormalities was not different in women with and without resting ST-T abnormalities (27% vs 23%, p = NS). In the entire population, independent predictors of an abnormal perfusion by multivariate analysis of clinical characteristics and risk factors were male gender (p <0.001, chi-square 10.5) and resting ST-T abnormalities (p <0.05, chi-sqaure 3). Separate analysis of patients based on gender revealed resting ST-T abnormalities as independent predictors of abnormal perfusion in men (p <0.05, chi-square 4) but not in women. Stress perfusion defect score was higher in men with than without ST-T abnormalities (887 ± 545 vs 207 ± 180, p <0.001). It is concluded that resting ST-T wave abnormalities are associated with a higher prevalence and severity of resting and dobutamine-induced myocardial perfusion abnormalities in men but not in women. Resting ST-T wave abnormalities are powerful predictors of compromised myocardial perfusion independent of other clinical risk factors of CAD in men.