Waldenström's macroglobulinaemia is a rare non-Hodgkin lymphoma with bone marrow involvement and serum immunoglobulin M monoclonal protein component. The most important risk factor is immunoglobulin M monoclonal gammopathy of undetermined significance. Clinical features vary but may include anaemia, neuropathy, infections and elevated serum viscosity. Diagnosis is confirmed by flow-cytometry made on bone marrow aspirate. Not all patients require treatment at diagnosis. The main therapeutic options include alkylating agents, nucleoside analogues and rituximab used in different combination regimens.