Purpose: For good quality of myocardial perfusion images, an approximately 30 min to 1 hour of waiting time after radiopharmaceutical injection and ingestion of fatty meal are asked of the patients. The aim of this study was to investigate the shortening of waiting time after radiopharmaceutical injection and improvement of image quality using natural plant extracts that promote bile excretion. Materials and Methods: Ten volunteers participated in protocol 1 (7 men, 3 women; mean age, 24.1¡¾2.4 years) and protocol 2 (8 men, 2 women; mean age, 26.1¡¾2.9 years), respectively. For the modified method of both protocols, subjects took natural plant extracts 15 minutes before the first injection of 99mTc MIBI without taking fatty meals. Control (Conventional) methods were performed with intake of a fatty meal 20 to 30 minutes after 99mTc MIBI injection. Results: As the results of protocol 1 and 2, the ratio of myocardial to lung ratio were not different between modified and conventional method. Liver to lung ratio of modified method showed significantly lower value than that of conventional method. In modified method, myocardial to liver ratio was higher persistently. In protocol 2, natural plant extracts took before the first injection of 99mTc MIBI exerted accelerating effect of excretion of bile juice into intestine until the end of examination. Conclusion: These results represent that natural plant extracts for facilitation of bile excretion before injection of 99mTc MIBI may provide better quality of myocardial perfusion images without the need for preparations such as ingestion of fatty meal within the 2 hours compared with conventional method.