Deletions of chromosome 6 at band q27 represent the site of a putative novel tumor suppressor gene in non-Hodgkin's lymphomas (NHL) of the immunocompetent host. Although several genetic lesions have been identified in AIDS-related NHL (AIDS-NHL), the involvement of 6q27 loss has not been investigated in this NHL category. In this report, we tested the presence of a 6q deletion at the molecular level in a panel of AIDS-NHL representative of the major histologic types, including AIDS-related small non-cleaved cell lymphoma (AIDS-SNCCL; n = 10), AIDS-related diffuse large cell lymphoma (AIDS-DLCL; n = 13) and AIDS-related anaplastic large cell lymphoma (AIDS-ALCL; n = 3). We report that 6q deletions occur in 5/26 AIDS-NHL tested (19.2%). Notably, 6q deletions do not randomly distribute throughout the spectrum of AIDS-NHL histologic types, but rather selectively cluster with AIDS-DLCL (5/13; 38.4%). Overall, these data add to the notion that the molecular pathogenesis of AIDS-NHL is heterogeneous and that distinct genetic pathways associate with specific histologic categories of AIDS-NHL.