Wegener's granulomatosis (WG) is a necrotizing and granulomatous vasculitis that usually affects the upper and lower respiratory tract and the kidneys. Cardiac involvement is rare although pericarditis, coronary arteritis, myocarditis, valvulitis and arrhythmias have been described. Acute myocardial infarction with clinical expression is an exceptional complication of Wegener's granulomatosis. We report a case of a 30-year-old man with Wegener's granulomatosis who suffered an acute myocardial infarction during the initial phase of the disease, following seven days of treatment with glucocorticoids and cyclophosphamide. Transthoracic echocardiography showed abnormal regional wall motion with septal hypokinesia and apical akinesia. Cardiac catheterization revealed an ectasic segment in the proximal left anterior descending coronary artery and total occlusion in the mid-segment. Medical therapy with prednisone and cyclophosphamide was continued. No complications and initial remission were achieved.