To date, 12 cases of primary leiomyosarcomas of the pulmonary artery have been described in the literature. In only 3 instances was a surgical treatment attempted. We describe a patient with pulmonary artery leiomyosarcoma presenting in obstructive shock. Surgical excision under extracorporeal circulation allowed temporary relief, but the patient died in septic shock on the 10th postoperative day. Relevant clinical and pathological data are briefly reviewed.