A 41-year-old woman underwent medical examination for superficial thrombophlebitis of both lower legs. Incidentally a chronic myelogenous leukemia was diagnosed and chemotherapeutically treated. Three weeks after the first attendance the patient again suffered superficial thrombophlebitides of all extremities. Clinically she exhibited symptoms of recurrent mild pulmonary embolization. Contrast venography revealed no signs of deep venous thrombosis of legs, pelvis, or cava inferior. Despite continuous full-dose intravenous heparin administration the patient died, with signs of fulminant pulmonary embolization. Surprisingly, necropsy revealed a complete thrombotic occlusion of the pulmonary arterial system caused by pulmonary arteritis with signs of recurrent pulmonary embolization from a parietal truncus pulmonalis thrombosis. In addition, an appositional growth of parietal thrombi central from peripheral arterial ramifications had occurred. Simultaneously, superficial thrombophlebitis of all extremities was observed without any additional signs of general vasculitis. There was no strong evidence for a causal relationship between the chronic myelogenous leukemia and pulmonary arteritis nor for any other underlying systemic disorder. Therefore we consider the pulmonary arteritis a possibly primary one. This very rare disease is discussed with respect to the literature.