A novel and convenient procedure for the synthesis of 3-acylindoles from simple indoles and aryl iodides has been established. Through ruthenium-catalyzed carbonylative C-H functionalization of indoles, with Mo(CO)6 as the solid CO source, the desired indol-3-yl aryl ketones were isolated in moderate to good yields. Not only N-alkylindoles but also N-H indoles can be applied here.