The results of chemotherapy in 24 patients with extramedullary plasmacytoma are reported. Complete regressions, including disappearance of monoclonal paraprotein and healing of bone lesions, were seen in 12 of 20 (60%) patients with disseminated disease. Extramedullary plasmacytoma responds better to chemotherapy than myeloma, and treatment should be pursued with vigour until all signs of disease have disappeared. Sensitivity to single-agent chemotherapy may vary, and if treatment fails with one agent, others should be tried.