Waldenstrφm’s macroglobulinemia (WM) is a neoplastic lymphoproliferative disease, characterized by clonal expansion of B-lymphocytes, which produce monoclonal immunoglobulin of the IgM type. A 77 year-old female presented with shortness of breath and a dry cough. Physical examination revealed absence of breath sounds over the base of the right lung. Blood tests showed anaemia, raised ESR and a monoclonal IgM protein. On chest X-ray right pleural effusion was found, and chest CT scan revealed multiple nodules of about 1cm in diameter in the lung parenchyma, mediastinal lymph node enlargement, and right-sided pleural effusion. Examination of the pleural fluid showed lymphoplasmacytic infiltration. Bronchoscopy and bronchoalveolar lavage were normal. Investigation for autoimmune disease and specific bacterial and viral diseases was negative. The bone marrow aspirate (BMA) showed diffuse infiltration by lymphoplasmacytoid cells (45%-50%) expressing CD20, CD19 and IgM, consistent with a diagnosis of WM. The patient underwent chemotherapy, which produced complete haematological remission and normalization of the chest CT scan. There was no evidence of disease one year later. The lungs are affected only 3%-5% of cases of WM. Pleuropulmonary involvement as the first manifestation of WM is extremely rare and only few cases have been reported in the literature. Pneumon 2008; 21(2):181–184