This pictorial essay reviews the pathophysiology and causes of mycotic aneurysms, their typical imaging appearances, mimics of mycotic aneurysms on CT, and treatment options. Correctly diagnosing mycotic aneurysms is critical for patient morbidity and mortality, as infected aneurysms are at extremely high risk of rapid growth and sudden rupture. The presence of a constellation of suggestive imaging features, as well as concerning patient symptomatology, should raise the possibility of a mycotic aneurysm.