Nasal natural killer (NK) lymphoma associated with Epstein-Barr virus (EBV) is a rare lymphoma that has not yet been reported in patients with human immunodeficiency virus (HIV). This report describes the first case, to our knowledge, of nasal NK cell lymphoma in an HIV-positive patient. A 50-year-old African man presented with an obstructive nasopharyngeal tumor, leading to the diagnosis of HIV infection. Nasal biopsy specimens showed NK cell lymphoma, confirmed on nasal tissues by morphologic, immunohistochemical, and polymerase chain reaction studies using a denaturing gradient gel electrophoresis technique that showed no T-cell receptor gamma rearrangement. The EBV was detected by in situ hybridization. The patient received chemotherapy but died from infection. To our knowledge, this is the first reported case of nasal NK cell lymphoma associated with EBV in an HIV patient. Involvement of EBV in HIV non-B-cell lymphomas may represent a further manifestation of opportunistic EBV infection arising in these patients.