Poxviruses are considered to be unique among DNA viruses because their infection cycle is carried out exclusively in the host cytoplasm. Such an infection strategy is of interest, because it necessitates generation of elaborate factories in which viral replication and assembly are promoted. By using imaging techniques, researchers showed that the infection cycle of the largest virus currently identified, the Acanthamoeba polyphaga Mimivirus, similarly occurs exclusively in the host cytoplasm. Newly synthesized mRNAs accumulate at discrete cytoplasmic sites that are distinct from the sites where virus replication occurs, and this is also observed in vaccinia infection. By revealing substantial physiologic similarity between poxviruses and Mimivirus and thus, implying that an entirely cytoplasmic viral replication might be more common than generally considered, these findings underscore the ability of DNA viruses to generate large and elaborate replication factories.