PURPOSE: The neutrophil/lymphocyte ratio (NLR) is a novel prognostic marker in several malignancies, whereas its function in patients with early-stage extranodal NK-T-cell lymphoma (ENKTL) hasn't been explored. Therefore, we expolored the predictive value of NLR for early-stage ENKTL in this study. METHODS: We evaluated the prognostic value of NLR in 132 patients with early-stage ENKTL based on L-asparaginase-containing regimens. Their characteristics, treatment responses, survival outcomes, prognostic factors, and the prognostic value of NLR were analyzed. RESULTS: All patients were followed up for median 54 months. The optimal NLR cutoff value was 3.77 by receiver operating curve(ROC). For all patients, the complete response (CR) and the overall response rate (ORR) were 74.2% and 85.6%. Patients with NLR < 3.77 had higher CR and ORR than patients with NLR ≥ 3.77(CR, 81% vs. 53.1%; ORR, 90% vs. 71.9%). For all patients, the 3-year overall survival (OS) and progression-free survival (PFS) based on L-asparaginase-containing chemotherapy were 80.4% and 76%. Patients with NLR < 3.77 had better survival outcomes than patients with NLR ≥ 3.77(3-year OS, 86.9% vs. 60.3%, p = 0.002; 3-year PFS, 81.8% vs. 54.5%, p = 0.001). By univariate and multivariate analyses, NLR ≥ 3.77 was an independent poor prognostic factor for both OS and PFS. Additionally, NLR ≥ 3.77 was associated with poor survival outcomes in patients with low-risk International Prognostic Index (IPI) and Prognostic Index of Natural Killer lymphoma with Epstein-Barr virus (PINK-E). CONCLUSION: A high NLR is a poor prognostic marker of survival in patients with early-stage ENKTL, and could be applied to risk-stratify for low-risk patients.