Coronary aneurysms are rare and of various etiologies in adults. Natural history, modalities of management and clinical monitoring remain poorly known due to the lack of large studies and homogeneous diagnostic and follow-up criteria in the published data. Coronary angiography is, so far, the most common diagnostic tool but can overlook some partially thrombosed aneurysmal. Intracoronary imaging, particularly intravascular ultrasound, can differentiate aneurysms from pseudoaneurysms considered by some to be at greater risk of events, requiring a curative treatment. Intracoronary imaging can also help with etiological assessment and percutaneous treatment. With its growing use in the search for coronary atheromatous disease, coronary CT angiography has become a major diagnostic tool for coronary aneurysms. In addition, that it can incidentally detect coronary aneurysms, coronary CT angiography is particularly useful for giant aneurysms poorly visualized on coronary angiography or less well evaluated by intracoronary imaging. It specifies their relationship with adjacent anatomical structures. It is also a non-invasive modality of monitoring. These three imaging tools are currently the most relevant in current practice pending large studies evaluating the natural history of coronary aneurysms, with the identification of possible risk factors that could modify the management.