The extrinsic compression of left main coronary artery (LMCA) by dilated pulmonary artery is rarely reported. Various congenital and acquired diseases were shown to cause extrinsic LMCA compression. Here we present a child with aortic root and LMCA compression due to dilated pulmonary trunk and causing angina like chest pain. The patient had also electrocardiographic evidence of myocardial ischemia. This case report will be a guide for the evaluation and surgical treatment of the patients with pulmonary hypertension and LMCA compression.