The 5'-untranslated region of the Oryza sativa alcohol dehydrogenase gene functions as a translational enhancer in monocotyledonous plant cells. The 5'-untranslated region (5'-UTR) functions as a translational enhancer in monocotyledonous plant cells is necessary to express a foreign gene efficiently. Here, we show that the 5'-UTR of the rice alcohol dehydrogenase gene contributes to efficient translation in not only dicotyledonous plant cells, but also in monocotyledonous rice cells.