© 2021 Umit Yavuz Malkan et al., published by De Gruyter.Autologous stem cell transplantation (ASCT) is one of the standard treatments of choice for eligible multiple myeloma (MM) patients. Herein, we aimed to analyze MM patients at our center and compare the clinical outcomes of single and double ASCT patients. Patients who were diagnosed as having MM and had undergone single or double ASCT in our clinic between the years 2003 and 2020 were retrospectively examined. In this study, the median time of second ASCT is approximately 3.6 years from the first ASCT. Overall survival (OS) duration of the single and double transplanted groups was 4,011 ± 266 vs 3,526 ± 326 days, respectively (p: 0.33). Progression-free survival (PFS) duration of the single and double transplanted groups was 2,344 ± 228 vs 685 ± 120 days, respectively (p: 0.22). Disease assessment after ASCT stable or progressive disease, partial remission, and very good partial or complete remission (CR) in single and double ASCT groups was 62/44/105 and 8/4/5, respectively (p: 0.22). The present study points out that the second ASCT treatment option for MM patients may not be effective as suggested, especially in the era of novel MM drugs, since our results come from the past data that novel drugs were not exist. In conclusion, we found no benefit with second ASCT in MM patients in terms of PFS and OS or CR rates, and the novel anti-myeloma drugs might decrease the need for a second transplant.