The better understanding of non-Hodgkin T-cell lymphoma is essential for establishing effective treatment strategy for non-Hodgkin T-cell lymphoma. Therefore, the data about conical features and treatment outcomes of each subtype should be accumulated to establish treatment strategy. However, the majority of previous data for non-Hodgkin T-cell lymphoma was from small case series of single institute. Furthermore, as novel drugs were developed for the treatment of relapsed or refractory T-cell lymphoma, the date from patients who were treated with those novel drugs are especially required because their outcomes may reflect the outcomes of currently available treatments. Thus, a multinational, multicenter prospective registry study is needed to provide information useful for establishing treatment strategies for T-cell lymphoma.