The purpose of this study is to clarify whether dynamic SPECT (DECT) immediately after the injection of 123I-15-(p-iodophenyl)-3-methyl pentadecanoic acid (BMIPP) may represent myocardial perfusion imaging. Ten patients with unstable angina pectoris (UAP), 11 patients with acute myocardial infarction (AMI) and 6 patients with non-ischemic heart disease (NIHD) were studied using BMIPP myocardial scintigraphy with DECT. DECT acquisition was started 2 minutes after the injection of BMIPP, and DECT images were obtained every three minute for 15 minutes with 3-headed gamma camera SPECT system. Additionally, static SPECT images were acquired 30 minutes after the injection of BMIPP. These SPECT images of BMIPP were compared with thallium-201 myocardial perfusion images at rest. In UAP group, early DECT images showed almost the same findings as thallium-201 images in 8 of 10 patients, and SPECT images at 30 minutes after the injection showed reduced accumulation of BMIPP compared with thallium-201 images in all patients. In AMI group, early DECT images showed the same findings as thallium-201 perfusion images in 9 of 11 patients, and SPECT images at 30 minutes after the injection showed reduced accumulation of BMIPP compared with thallium-201 images in 5 of 11 patients. These results indicate that myocardial perfusion can be evaluated in the early image using DECT, in addition to myocardial fatty acid metabolism in the delayed image.