The incidence of multiple myeloma, a monoclonal gammopathy, increases dramatically with age. The disorder involves a malignant proliferation of plasma cells, which results in abnormal production of immunoglobulin, bone-marrow infiltration, destruction of bone, renal failure, and infection. A number of treatment regimens can achieve remissions in approximately 50 per cent of patients. The elderly appear to be able to tolerate such therapy well and with results equivalent to those in younger individuals.