Non-Hodgkin's lymphomas (NHL) are part of the spectrum of disease associated with HIV infection. However, there are only occasional reports of NHL of T-cell origin in HIV-infected patients. A previously asymptomatic HIV-infected man, who was seronegative for human T-lymphotropic virus type I antibodies, developed a high-grade peripheral T-cell lymphoma of anaplastic large-cell type which was Ki-1 + (CD30 +), HLA-DR +, epithelial membrane antigen +, CD25 +, CD71+, CD2+ and CD5 +. Pan-B markers CD19 and CD22 and histiocytic marker CD68 were negative. At diagnosis the patient had 0.3 × 109/l T-helper lymphocytes. The response to chemotherapy was dramatic and the patient is alive and disease-free 18 months after treatment. A review of previously described peripheral T-cell lymphomas in HIV-positive indivduals is performed, and we conclude that the spectrum of neoplasms in such cases is probably broader than originally thought.