Peripheral T and NK lymphomas of the nasal cavity are a heterogeneous group of neoplasia of lymphocytic origin. Nasal T/NK lymphoma is a rare and severe disorder in Africa and Europe. It is an aggressive form of non-Hodgkin's lymphoma with specific clinicopathological features. Diagnosis is based on immunohistochemical study. Treatment includes chemotherapy and radiotherapy. This type of lymphoma has a poor prognosis overall, even with treatment. We report a case of T / NK lymphoma simulating an orbito-jugal cellulitis. This is the case of a 49-year-old patient admitted with an extended left facial cellulitis. The CT scan of the facial mass showed a left unilateral pansinusitis with orbital infiltration. The diagnosis was made after an immunohistochemical study of the nasal biopsies. Histological examination revealed nasal-type T / NK lymphoma. The treatment consisted of radio-chemotherapy. T / NK lymphomas are aggressive; they mainly affect the nasal sinus cavities. They are responsible for angio-destruction and necrosis which make the symptoms nonspecific and the biopsies often negative, causing a problem of differential diagnosis. The treatment is based on radiotherapy and chemotherapy and the prognosis remains poor. The patient was treated with CHOEP chemotherapy followed by radiotherapy.