This study examines the utilization patterns of myocardial perfusion imaging (MPI) and cardiac catheterization (CC) under Taiwan's national health insurance program. This study used the longitudinal health insurance database with 1,000,000 people were randomly selected from the national health insurance research database. This study obtained data from these patients with coronary artery disease (CAD) and comparison with the utilization of MPI or CC between 2005 and 2009. The incidence of CAD did not significantly change, while the prevalence of CAD, utilization of MPI, and the utilization of CC for the CAD patients increased annually. There were the most CAD patients in Northern Taiwan (43.5%), followed by Southern, Central, and Eastern Taiwan. The utilizations of both of MPI (12.7 per 100 CAD patients) and CC (10.6 per 100 CAD patients) were most frequent in Northern Taiwan followed by Southern, Central, and Eastern Taiwan. However, the MPI/CC ratio was 1.20 in Northern Taiwan, followed by Southern, Central, and EasternTaiwan (0.88, 0.64, and 0.52, respectively, P = 0.0008). The use of MPI was higher than CC only in Northern Taiwan. MPI may be underutilized to serve the role of gatekeeper for CC in the other regions.