Objectives: The optimal treatment strategy for early-stage natural killer/T-cell lymphoma (NKTCL) remains unclear. This study aimed to evaluate and compare the clinical outcomes and adverse events (AEs) associated with two treatment regimens for early-stage NKTCL: pegaspargase with concurrent radiation therapy (P+CCRT) and pegaspargase, gemcitabine, and oxaliplatin (P-GEMOX) with sequential radiation therapy (SERT). Propensity score matching (PSM) was employed to ensure balanced comparison between these regimens. Methods: We assessed the efficacy of P+CCRT from a phase II trial and P-GEMOX combined with SERT using real-world data. PSM was conducted at a 1:1 ratio with a caliper of 0.18 to align baseline characteristics between the treatment groups. Key outcomes analyzed included overall response rate (ORR), complete response rate (CR), progression-free survival (PFS), overall survival (OS), and AEs. Results: Following PSM, the study included 52 patients, with 26 in each treatment group. Baseline characteristics were balanced between the cohorts. The ORR for P+CCRT group was 100.0% compared to 88.5% for P-GEMOX+ SERT group, and the CR rates was 100.0% vs. 76.9%, respectively. The 3year OS and PFS rates were both 92.3% for P+CCRT, while P-GEMOX showed 92.3% OS and 80.8% PFS. Adverse events, including hematological toxicity, hepatotoxicity, and coagulation dysfunction, were comparable between the two regimens. Conclusion: P+CCRT is associated with comparable clinical outcomes compared to P-GEMOX + SERT in early-stage NKTCL, with comparable adverse events. Additionally, P+CCRT offers the benefit of a more streamlined treatment regimen with a shorter cycle. Given these encouraging results, further cohort studies are needed to validate these results.