A highly efficient cross-coupling reaction of monofluoroalkenes with tertiary, secondary, and primary alkyl and aryl Grignard reagents in the presence of a catalytic amount of copper or nickel catalyst, respectively, has been developed. The reactions proceeded smoothly at room temperature, providing (E)-alkene isomers in moderate to high yields. Plausible mechanisms of the Ni-catalyzed coupling reaction of monofluoroalkene with Grignard reagents are suggested.