To evaluate the clinical efficacy of 99Tcm-MIBI myocardial tomography for detecting coronary artery disease (CAD) 115 consecutive patients who underwent both 99Tcm-MIBI single photon emission computed tomography (SPECT) and coronary arteriography were studied. Thirty-three patients without and 82 with significant coronary artery disease were documented by coronary arteriography. The overall sensitivity and specificity of 99Tcm-MIBI SPECT for detecting coronary artery disease were 96 and 87.9%, respectively. The sensitivity for identifying patients with CAD without myocardial infarction was 88%. The sensitivity of 99Tcm-MIBI SPECT for detecting individual coronary artery lesions was 86% for left anterior descending artery (LAD), 69% for left circumflex artery (Lcx) and 86% for right coronary artery (RCA), lesions respectively. In conclusion, 99Tcm-MIBI SPECT provides a reliable method for detecting CAD.