Technetium-99m-sestamibi (MIBI) and 99mTc-teboroxime (TEBO) are two new myocardial perfusion imaging agents. The purpose of this prospective study was to compare MIBI and TEBO to 201TI planar imaging. Eighteen patients with significant coronary artery disease on coronary angiogram were submitted to three treadmill stress tests performed within 3 mo and were imaged with the three radiopharmaceuticals as follows. 1. TI: 2.2 mCi, immediate and delayed views (4 hr later, 8 min/view). 2. TEBO: 15-20 mCi at stress (1 min/view) and a second injection was repeated 4 hr later at rest (20-25 mCi). 3. MIBI: 15-18 mCi at stress (8 min/view) and 1-4 days later, 15-18 mCi at rest. Patients achieved similar levels of exercise. A blinded reading was performed by three observers. The left ventricle was divided into three segments/view and ischemic/normal wall ratios were also determined. Segmental comparison showed an agreement in 85% (138/162) of the segments between TI and TEBO, in 92% (149/162) between TI and MIBI and in 84% (136/162) between MIBI and TEBO. Abnormal TI, MIBI and TEBO studies were seen in 16 (89%), 16 (89%) and 15 (83%) patients, respectively, detecting 77, 75 and 65 abnormal segments. Ischemic-to-normal wall ratios were 0.75 +/- 0.06, 0.73 +/- 0.08 and 0.78 +/- 0.08 for TI, MIBI and TEBO, respectively. In conclusion, although the biologic characteristics of these agents are different, this study showed a good correlation between them in detection of significant coronary artery disease (high pretest likelihood population).