We report three patients with AL amyloidosis manifesting as systemic lymphadenopathy, mainly in the cervical and supraclavicular regions. Histopathology of lymph nodes showed massive deposition of AL amyloid with no abnormal findings suggestive of lymphoproliferative disorders. Two of the patients were considered to be classifiable as primary systemic AL amyloidosis based on the presence of M-protein in serum and abnormal plasma cells or lymphoplasmacytoid cells in the bone marrow probably producing the precursor immunoglobulin, although no visceral organs were affected. The size of the involved lymph nodes in these two patients increased gradually, and one was treated with rituximab and VAD (vincristine, doxorubicin and dexamethasone) followed by high-dose melphalan with autologous peripheral blood stem cell transplantation (auto-PBSCT). The remaining patient showed no obvious change in the size of lymph nodes or detectable M-protein in serum. The prognosis of AL amyloidosis manifesting as lymphadenopathy is usually good as long as there are no hematological malignancies or rapid increases in the size of lymph nodes, but in cases of the systemic type, intensive chemotherapy, such as high-dose melphalan with auto-PBSCT, should be actively considered in order to avoid possible involvement of visceral organs.