ABSTRACTBackground: Peripheral T-cell lymphomas (PTCL) are an aggressive group of mature T-cell neoplasms, often associated with poor outcomes, in part, due to frequent relapsed/refractory disease. The objective of this study was to assess the prognostic impact of disease progression within 24 months (POD24) on overall survival (OS) for patients diagnosed with PTCL.Methods: A retrospective analysis was conducted on a cohort of patients with newly diagnosed PTCL who underwent chemotherapy at the Affiliated Hospital of Xuzhou Medical University between January 2010 and September 2021. Prognostic assessment was limited to patients who were evaluable for POD24.Results: Records were reviewed for 106 patients with PTCL, of whom 66 patients experienced POD24 (referred to as the POD24 group) and 40 patients did not experience POD24 (referred to as the no POD24 group). Significant differences were observed between the POD24 group and the no POD24 group in regard to clinical stage, Eastern Cooperative Oncology Group (ECOG) performance status (PS), International Prognostic Index (IPI) score, lactate dehydrogenase (LDH) levels, β2-microglobulin (β2-MG) levels, prealbumin and albumin levels. Patients in the POD24 group had a significant shorter median OS compared to the no POD24 group (11.9 months vs not reached, respectively; P < 0.001). Non response (NR) to treatment and POD24 were identified as independent negative prognostic factors for survival in patients with PTCL.Conclusion: POD24 is a prognostic factor associated with unfavorable outcomes in patients with PTCL and can be used to identify high-risk patients and guide treatment decisions.