Sarcoidosis, a chronic granulomatous disease with unknown etiology and pathogenesis, affects the skin and many other organs and has a course characterized by remissions and relapses. We describe a patient with sarcoidosis, which we diagnosed retrospectively after we had difficulties in harvesting the left internal thoracic artery because of giant and disseminated mediastinal lymphadenopathies on the anterior thoracic wall during urgent coronary artery bypass surgery.