To evaluate the usefulness of 123I-BMIPP as a tracer of fatty acid metabolism in patients with angina pectoris, we performed rest BMIPP myocardial SPECT and stress 201Tl SPECT in 20 patients with angina pectoris. BMIPP SPECT was evaluated in the defected regions with Tl redistribution. Abnormal findings in BMIPP were observed in 11 of 20 patients and in 14 of 29 myocardial segments with Tl redistribution. Such decreased uptake was observed more often in patients with multivessel disease (64% vs. 12%). In addition, the decreased BMIPP uptake was seen more often in the segments exhibiting hypokinesis than the segments showing with normal wall motion. Thus, BMIPP imaging may be available to detect myocardial ischemia, particularly in patients with severe coronary disease.