Coronary artery disease affects thousands of Icelanders and is the most common cause of death in Iceland. In recent years great strides have been taken towards deeper understanding and improved treatment of this common disease, resulting in markedly improved outcomes. This evidence based review article is the first of two on coronary artery diseases. It will discuss the epidemiology and pathogenesis of coronary artery disease but also clinical presentation and diagnostic work-up. The review is aimed at a wide readership of physicians, other health care providers and students of health sciences. Current literature will be reviewed with special focus on recent Icelandic studies.