Atherosclerosis is the main cause of coronary artery aneurysm, however they can be observed in connective tissue diseases such as systemic lupus erythematosus and vasculitis. Kawasaki’s disease and polyarteritis nodosa (PAN) are the systemic vasculitis that more often present coronary artery aneurysms. There are descriptions in the literature that small vessel vasculitis such as microscopic polyangiitis and PAN could develop coronary artery aneurysm, which are infrequent in other ANCA-associated vasculitis. Here, we report the case of a 25-year-old man who developed an extensive anterior myocardial infarct. The coronary angiogram showed coronary artery aneurysms, on laboratory ANCA C positivity with elevated levels of anti-proteinase 3 antibodies were present. He was treated with high doses of corticosteroids and cyclophosphamide with resolution of the aneurysms.