We describe treatment of a patient with advanced extranodal NK/T-cell lymphoma, nasal type, with multiple subcutaneous lesions and hemophagocytic syndrome. Considering the projected poor outcome of conventional treatments, we designed an L-asparaginase-based induction therapy. L-asparaginase (4000 units/day, day 1 to day 7) combined with vincristine (1 mg, day 1) and prednisolone (100 mg/day, day 1 to day 5) was administered by intravenous infusion every 3 weeks. Within a week after treatment was started, excellent response was observed. Because of an allergic reaction to L-asparaginase, 6 courses of CHOP (adriamycin, cyclophosphamide, vincristine and prednisolone) therapy were administered as consolidation after 4 courses of L-asparaginase. The lymphoma was controlled with complete remission lasting longer than 2 years without additional treatment. These results and related reports may contribute to greater therapeutic efficacy against at least some cases of extranodal NK/T-cell lymphoma and other related diseases. Further evaluations based on clinical study are expected to clarify these results.