BACKGROUND The non-invasive diagnosis of coronary artery disease in women remains a difficult clinical problem. The aim of this study was to investigate the comparative diagnostic accuracy of dobutamine stress echocardiography and stress thallium-201 single-photon-emission computed tomography (SPECT) in women who were suspected to have coronary artery disease. METHODS We studied 70 consecutive women who had not had a previous myocardial infarction (mean age 65 years) who underwent dobutamine stress echocardiography and quantitative coronary angiography. Sixty-one of the 70 women were also subjected to thallium-201 SPECT, with exercise or dipyridamole administration as the stressor, during the same period. A positive diagnosis was based on the detection of inducible wall motion abnormality and the presence of stress-induced abnormalities of perfusion. RESULTS No significant complication occurred in any patient during dobutamine stress echocardiography (peak dose 31 +/- 9 micrograms/kg per min, atropine administered to 13 patients, peak heart rate 120 +/- 19 beats/min). Coronary artery disease (> or = 50% diameter stenosis) was present in 20 (29%) patients, nine with one-vessel and 11 with multivessel disease. The sensitivity, specificity and diagnostic accuracy of dobutamine stress echocardiography for detecting coronary artery disease were 75, 92 and 87% respectively. In 61 patients who underwent both stress tests, the sensitivity, specificity and accuracy of dobutamine stress echocardiography and stress thallium-201 SPECT were 72 versus 78%, 91 versus 70% (P < 0.05) and 85 versus 72%, respectively. CONCLUSIONS Dobutamine stress echocardiography appears to be of comparable sensitivity and higher specificity with stress thallium-201 SPECT for noninvasive detection of coronary artery disease in women.