In order to understand the role of the 3'-terminal untranslated region (3'-UTR) of alfalfa mosaic virus (A1MV) RNA 4 in viral RNA translation we have constructed the RNA derivatives differing in the length of their 3'-terminal portions and expressed them in a wheat germ extract. The result shows that the removal of the 3'-UTR from A1MV RNA 4 causes a lagged RNA translation in the cell-free system as compared with the translation of the full length RNA 4, thus suggesting the involvement of the 3'-UTR in the translation initiation pathway.