The optimal treatment strategy for relapsed natural killer/T-cell lymphoma (NKTCL) remains largely unknown. We retrospectively reviewed the treatment modalities and prognosis of 56 relapsed NKTCL patients. Chemotherapy was the initial salvage treatment, followed by radiotherapy (RT) or autologous hematopoietic stem cell transplantation (AHSCT) as consolidative therapy, depending on the status of remission and the pattern of relapse. For patients with locoregional relapse alone, consolidative RT after salvage chemotherapy significantly improved prognosis compared with follow-up (5-year OS: 83.3 vs. 41.7%, P = 0.047). For patients with distant relapse, consolidative AHSCT after salvage chemotherapy significantly prolonged survival compared with follow-up (2-year OS: 100.0 vs. 20.0%, P = 0.004). Patients without consolidative treatment after response to salvage chemotherapy exhibited a comparable survival to those who experienced stable or progressive disease after chemotherapy. Asparaginase (ASP)-containing salvage chemotherapy failed to confer a survival advantage over ASP-absent chemotherapy (5-year OS: 44.2 vs. 39.3%, P = 0.369). In conclusion, consolidative RT or AHSCT improved prognosis in patients with relapsed NKTCL who responded to initial salvage chemotherapy, and the role of ASP in salvage chemotherapy requires further exploration in prospective studies.