Extrinsic compression due to pulmonary artery enlargement from severe pulmonary hypertension is an uncommon cause of hemodynamically significant left main artery stenosis. Patients with severe pulmonary hypertension who experience angina should be evaluated for possible extrinsic compression of the left main artery due to pulmonary artery enlargement. Although computed tomographic angiography and cardiac magnetic resonance imaging are helpful in the screening for extrinsic left main artery compression, coronary angiography is the gold standard for the diagnosis. Percutaneous coronary intervention of the left main artery is feasible, safe, and a reasonable initial revascularization strategy for these patients because of the high risk of postoperative right ventricular failure and mortality observed with bypass surgery.