We analyzed the treatment responses, toxicities, and survival outcomes of patients with relapsed or refractory multiple myeloma who received daily thalidomide, cyclophosphamide, and dexamethasone (CTD) or daily thalidomide, melphalan, and prednisolone (MTP) at 17 medical centers in Korea. Three-hundred and seventy-six patients were enrolled. The combined chemotherapy of thalidomide, corticosteroid, and an alkylating agent (TAS) was second-line chemotherapy in 142 (37.8%) patients, and third-line chemotherapy in 135 (35.9%) patients. The response rate overall was 69.4%. Patients who were not treated with bortezomib and lenalidomide before TAS showed a higher response rate compared to those who were exposed to these agents. The estimated median progression-free survival and overall survival times were 10.4 months and 28.0 months, respectively. The adverse events during TAS were generally tolerable, but 39 (10.4%) patients experienced severe infectious complications. There were no differences in terms of efficacy between CTD and MTP, but infectious complications were more common in CTD group. TAS is an effective treatment regimen which induces a high response rate in relapsed or refractory multiple myeloma patients. Due to the high incidence of grade 3 or 4 infection, proper management of infection is necessary during the TAS treatment, especially the CTD.