To evaluate clinical value of 99mTc-1,2-bis[bis (2-ethoxyethyl)phosphino]ethane(99mTc-PPN1011) imaging for assessing coronary artery disease (CAD), 99mTc-PPN1011 SPECT imaging at post-exercise and at rest was compared with 201Tl SPECT imaging at post-exercise and 3 hours in 24 patients with CAD. The sensitivities for detecting CAD were 100% (21/21) by 99mTc-PPN1011 SPECT and 95% (20/21) by 201Tl SPECT. The sensitivities for detecting stenosed coronary arteries (> or = 75% stenosis) were similar between 99mTc-PPN1011 (68%) and 201Tl (66%). The similar specificity values were obtained by 99mTc-PPN1011 (80%) and 201Tl (77%). The patterns of abnormality (normal, ischemia and scar) were concordant between 99mTc-PPN1011 and 201Tl images in 20 of the 24 cases (83%) and 106 of the 120 segments (88%). In the simultaneous analysis of cardiac function by first pass radionuclide angiography with 99mTc-PPN1011, there was good correlation between left ventricular ejection fraction and perfusion score at rest (r = 0.70) and exercise (r = 0.80). The degrees of abnormality between perfusion and wall motion were similar in 56 of 66 segments (85%) at rest and 52 of 66 segments (79%) at exercise. We conclude that this agent is promising for the diagnosis and evaluation of coronary artery disease.