Arterial involvement in Behçet's disease (BD) is less common than venous lesions.

The most commonly affected arteries are:

the aorta, lower extremity arteries, mesenteric, femoral, coronary, renal, subclavian and pulmonary arteries. The rupture of pulmonary arteries is the main cause of death of patients with EB and the presence of aneurysms is a bad prognostic factor. We report two patients with arterial involvement in BD. A 14 years old male presenting with hemoptysis lasting three days. A chest computed tomography showed an aneurismal dilatation of the right interlobar artery, bilateral intramural thrombi and alveolar hemorrhage. A right lobar pulmonary resection was performed but hemoptysis recurred. Suspecting a BD, prednisone was started and hemoptysis subsided. A 42 years old male presenting with chest pain and hemoptysis. A chest CT scan showed thrombi in pulmonary veins and anticoagulant therapy was started. Two months later he was admitted again due to a massive hemoptysis. The CT scan showed aneurisms in pulmonary arteries, mural thrombi and pulmonary infarction. With the diagnosis of BD, methylprednisolone, followed by prednisone and cyclophosphamide were used, with a good clinical response.