Diabetes mellitus is one of the major causes of cardiovascular morbidity and mortality, and its prevalence is increasing. Although there have been great efforts regarding the early diagnosis and treatment of coronary artery disease in diabetic patients with the development of non-invasive imaging modalities, many diabetic patients are still managed with invasive coronary therapies such as percutaneous coronary intervention or coronary artery bypass graft in clinical practice. Coronary angiography is a gold standard method for detecting and treating coronary artery disease; however, this method is invasive and thus can elicit a relatively higher prevalence of procedure-related complications than non-invasive diagnostic methods. Accordingly, the appropriate use of coronary angiography could play an important role in the reduction of unnecessary complications as well as physician decision making. Recently, appropriate use criteria for coronary angiography in many types of patients with suspected or known coronary artery disease have been documented. This article demonstrates several aspects to be considered when performing coronary angiography and the appropriate use criteria of coronary angiography in diabetic patients.