Waldenstrom macroglobulinemia (WMG), a proliferation of malignant monoclonal IgM secreting plasmacytoid lymphocytes in lymph nodes, spleen, and marrow, usually pursues a chronic clinical course. A patient with WMG for five years who developed pulmonary tumors consisting of plasmacytoid lymphocytes prompted a review of the literature for pulmonary manifestations of WMG. Twenty-six males and 18 females, ranging in age from 33 to 84 years, have been reported with histologically proven pulmonary involvement by WMG. The x-ray findings, evident in most patients when first seen, consisted of masses (22 patients), inflitrates (31 patients), and pleural effusions (19 patients). Most patients (24) had two or more of these manifestations but only five, in addition to our patient, had isolated pulmonary nodules. Isolated pulmonary infiltrates were found in ten patients and isolated pleural effusions in only four. Symptoms at the onset of pulmonary involvement included dyspnea (54%), nonproductive cough (33%), and chest pain (7%); 15% were asymptomatic. Pulmonary manifestations, like other features of WMG, respond to alkylating agents or irradiation and do not appear to affect prognosis adversely. Pulmonary involvement should be suspected in any patient with WMG who develops an abnormal chest x-ray.