The reticuloendotheliosis viruses (REV) spleen necrosis virus (SNV) and reticuloendotheliosis virus strain-A (REV-A) are amphotropic retroviruses which infect a large variety of cells of avian and some mammalian species. They normally do not infect primate or rodent cells. However, they efficiently infect and integrate their genome into that of human cells when they are pseudotyped with the envelope protein of other mammalian retroviruses or the G protein of vesicular stomatitis virus (VSV) or rabies viruses (RV). Moreover, SNV-derived retroviral vectors, which display single chain antibodies or other targeting ligands on the viral surface enable cell-type-specific gene delivery into various human cells. My laboratory has developed genetically engineered REV vectors, which are capable of infecting non-dividing cells such as quiescent human T-cells, primary monocyte-derived macrophages, and mature neurons. Thus, REV-derived vectors appear to be very interesting candidates for the further development of vectors for human gene therapy. This article reviews the replication of REVs and vectors derived from REV-A and SNV for gene transfer into human cells.