With the advent of asparaginase-based drugs, patients with natural killer/T-cell lymphoma (NKTCL) have achieved excellent efficacy. However, the prognosis is poor in patients with advanced disease, and even worse in relapse/refractory patients. This meta-analysis aimed to evaluate the efficacy and safety of PD-1/PD-L1 inhibitor monotherapy or combination treatment strategies in patients with NKTCL.Seven databases were extensively searched from inception to November 2023 and updated in April 2024, with no language restrictions. The pooled overall response rate (ORR), overall survival (OS), progression-free survival (PFS), and treatment-related adverse events (AEs) were calculated via a random effects model. Heterogeneity was tested utilizing the I-square (I2) test and Cochrane's Q test. Subgroup analysis was used to compare the effects of single PD-1/PD-L1 inhibitors or combination treatment in NKTCL patients.A total of thirteen single-arm studies involving 460 patients were enrolled. The results revealed that the pooled ORR was 62% (95% CI: 48-76%). In terms of survival outcomes, the pooled 1-year OS was 67% (95% CI: 47-87%) and the 2-year OS was 47% (95% CI: 24-69%). Moreover, the 1-year and 2-year PFS rates were 66% (95% CI: 48-84%) and 59% (95% CI: 34-84%), respectively. With regard to treatment toxicity, the pooled incidence of all-grade AEs was 86% (95% CI: 79-93%), and the pooled incidence of grade 3 or higher AEs was 29% (95% CI: 22-36%). Leukopenia and hypoalbuminemia were identified as the most common hematologic and non-hematologic adverse events, respectively.Evidence suggests that PD-1/PD-L1 inhibitors are promising treatment options for newly diagnosed NKTCL patients. PD-1/PD-L1 inhibitors combined with chemotherapy or chidamide has demonstrated superior clinical efficacy in patients with relapsed/refractory NKTCL.Open Science Framwork: osf.io/2bwh3.© 2025. The Author(s).