Angiosarcoma in the lung is an uncommon disorder and is usually attributable to metastasis from a primary site. Primary pulmonary angiosarcoma is extremely rare, and the prognosis of affected individuals is dismal, with most patients dying within months of presentation. Indeed, there have been no reported instances of successful treatment of this condition. We now report the case of a patient with primary pulmonary angiosarcoma who responded to a combination of radiotherapy and immunotherapy with recombinant interleukin-2. The patient remains well without signs of recurrence 1 year after initial presentation. This combination therapy may be a promising strategy to prolong the survival of patients with primary pulmonary angiosarcoma.