Objective: A major cause of hemophagocytic lymphohistiocytosis (HLH) is malignant neoplasms of the blood system, among which NK/T cell lymphoma is one of the most common risk factors. Patients with NK/T cell lymphoma hemophagocytic lymphohistiocytosis (NK/T-LAHS) have a worse prognosis and higher mortality. We aimed to explore the factors that affect the prognosis of NK/T-LAHS. Methods: Clinical data of 42 patients with NK/T-LAHS diagnosed by Beijing Friendship Hospital from June 2008 to June 2016 were analyzed retrospectively. The survival time was counted until 1 August 2016. Results: For the 42 NK/T-LAHS patients, 1-month survival rate was 48.9%, 2-month survival rate was 36.7%, 3-month survival rate was 28.8%, 6-month survival rate was 23.0%, and 12-month survival rate was 15.4%. NK/T-LAHS patients who underwent allogeneic hematopoietic stem cell transplantation (Allo-HSCT) (p = 0.000), exhibited peripheral blood Epstein-Barr virus (EBV)-positivity (p = 0.004), and achieved overall response (OR) remission after initial induction therapy (p = 0.007) had statistical significance. Conclusion: NK/T-LAHS is a disease of poor prognosis and high mortality. NK/T-LAHS patients who achieved OR remission after the initial induction therapy had a better prognosis than non-remission patients and Allo-HSCT was an effective way to prolong the survival of NK/T-LAHS patients. However, EBV positivity in peripheral blood was a poor prognostic factor in NK/T-LAHS patients.