We had experienced a case of Waldenström's macroglobulinemia in 45-year-old man, who visited the outpatient department of internal medicine due to bleeding diathesis of nose and gum, multiple lymphadenopathy, and general fatigue. Physical examination revealed mild hepatosplenomegaly and generalized lymphadenopathy. Serum protein electrophoresis shows the monoclonal gammopathy at the late beta-fraction. By the immunoelectrophorsis of serum protein, IgM, lambda-type macroglobulinemia was confirmed. Bone marrow smear and biopsy shows 61% of plasmocytoid lymphocytes atypical lymphocyte and mature and immature plasma cells. Cervical lymph node biopsy shows obliteration of normal structure by diffuse proliferation of plasmacytoid lymphocytes and histiocytes in subcapsular sinus, cortex and medulla. PAS positive intranuclear and intracytoplasmic inclusion bodies were seen in plasmacytoid lymphocytes. By electron microscopic findings of cervical lymph node, dilated rough endoplasmic reticulum which was filled with electron-light density and pale amorphous material. Intracytoplasmic and intranuclear inclusion bodies containing the same density material were seen.