We report on a 67-year-old man with Felty's syndrome (FS) complicated by recurrent pneumonia and an infected wound, which was not healing in spite of maximal antibiotic and local therapy. Encouraged by previous experience, we treated him with granulocyte-macrophage colony-stimulating factor (GM-CSF). His total leukocyte count rose, but the patient's pneumonia deteriorated. In addition, a previously known chronic obstructive lung disease (COLD) was exacerbated acutely. These complications finally led to his death. Postmortem examination revealed widespread pneumonia with invasive aspergillosis and a peripheral adenocarcinoma in his left lung.