Nasal-type extranodal natural killer (NK)/T-cell lymphoma (ENKL) is a highly invasive cancer with a poor prognosis. More effective and safer treatment regimens for ENKL are needed. Pegaspargase (PEG-Asp) has a similar mechanism of action to L-asparaginase (L-Asp), but presents lower antigenicity. The aim of the present research was to evaluate the safety profile and the latent efficacy of a PEG-Asp-based treatment regimen in patients with ENKL. Data collected from 20 patients with histologically confirmed ENKL, admitted to the Third Affiliated Hospital of Sun Yat-Sen University from January 2009 to August 2013, were included in the study. All patients received 2500 IU/m2/IM PEG-Asp on day 1 of every 21-day treatment cycle. Patients received combination chemotherapy with CHOP (n=5), EPOCH (n=7), GEMOX (n=7) or CHOP with bleomycin (n=1). After 2-5 treatment cycles (median, 4 cycles) of PEG-Asp-based chemotherapy, five patients (25%) showed a complete response (CR), and the overall response rate (ORR) was 60%. Grade 3/4 neutropenia occurred in fourteen patients (70%). Grade 3 alanine aminotransferase (ALT) elevation was observed in two. Grade 1-2 non-hematological toxicity consisted of activated partial thromboplastin time (APTT) elongation (n=9), hypofibrinogenemia (n=6),hypoproteinemia (n=17), hyperglycemia (n=3), and nausea (n=6). No allergic reactions were detected. No treatment related death was reported. Our results suggested that PEG-Asp-based chemotherapy presented an acceptabletolerance and a potential short-term outcome in patients with nasal-type ENKL.