Extranodal natural killer (NK)/T-cell lymphoma, nasal type, has a unique geographic distribution. Its pathology is characterized by marked angio-invasion and tissue necrosis. A typical NK-cell phenotype is usually present: CD2+, CD3 epsilon+, CD56+, cytotoxic molecules+ and Epstein–Barr virus (EBV)+. Magnetic Resonance Imaging helps to clearly define the local involvement. Positron Emission Tomography helps to demonstrate system spread. Various prognostic variables (International Prognostic Index or the Korean Prognostic Index) should be documented. This may include quantification of plasma EBV DNA. For localized nasal disease, radiotherapy is important, although chemotherapy is often added. Sustainable remission is observed in over half of these patients. For extra-nasal or disseminated disease, systemic chemotherapy becomes the mainstay and the prognosis is usually poor. Doxorubicin-containing regimens are not entirely satisfactory and l-asparaginase containing regimens are being investigated. Patients with poor prognostic features may be considered for an early autologous haematopoietic stem cell transplant. Allogenetic transplantation is efficacious but is associated with high transplant-related mortality.