We present a case of giant coronary arteriovenous fistula between left main coronary artery and pulmonary artery in a 60-year-old female who presented with anginal symptom. Dobutamine stress echocardiography and myocardial perfusion scan with ^99mTc-MIBI revealed a reversible perfusion defect in the septal region. Coronary angiography demonstrated a giant coronary arteriovenous fistula origination from the left main coronary artery and draining into the pulmonary artery. This appears to be the first case in which dobutamine stress echocardiography and myocardial perfusion scan with ^99mTc-MIBI demonstrated myocardial ischemia due to coronary steal in patient with a coronary arteriovenous fistula.