In the process of translation of eukaryotic mRNAs, the 5' cap and the 3' poly(A) tail interact synergistically to stimulate protein synthesis. Unlike its cellular counterparts, the small mRNA (SmRNA) of Andes hantavirus (ANDV), a member of the Bunyaviridae, lacks a 3' poly(A) tail. Here we report that the 3' untranslated region (3'UTR) of the ANDV SmRNA functionally replaces a poly(A) tail and synergistically stimulates cap-dependent translation initiation from the viral mRNA. Stimulation of translation by the 3'UTR of the ANDV SmRNA was found to be independent of viral proteins and of host poly(A)-binding protein.