Heart disease is one of the leading causes of deaths in Korea, along with malignant neoplasms and cerebrovascular diseases. The proper diagnosis and management for patients with suspected heart diseases should be warranted for the public health care. Advances in CT technology have allowed detailed images of the heart to be obtained, which enable evaluations not only of the coronary arteries but also of other cardiac structures. Currently, the latest multi-detector CT machines are widespread around Korea. The appropriate use of cardiac CT may lead to improvements of the physicians' medical performances and to reduce medical costs which eventually contribute to promotions of public health. However, until now, there has been no guidelines regarding the appropriate use of cardiac CT in Korea. We intend to provide guidelines for the appropriate use of cardiac CT in heart diseases based on scientific data. The purpose of this guideline is to assist the clinicians and other health professionals when using cardiac CT for diagnosis and treatments of heart diseases.