We report a patient with multiple myeloma who was treated with pamidronate disodium every 3 weeks for 18 months without any other chemotherapeutic agents. Pamidronate therapy resulted in a marked reduction of marrow plasmacytosis and serum paraprotein levels, and recovery from anemia together with an increase in bone mineral density (BMD). To our knowledge, this is only the third report in which bisphosphonates showed anti-myeloma effects in humans and the result suggests that the compound has a clinically useful anti-tumor effect.