A novel method for the synthesis of stereodefined cyclopropyl-substituted alkenes, based on the Suzuki-type cross-coupling reaction between cyclopropylboronic acids and various alkenyl triflates, is described. It was found that the environment of the alkenyl triflate plays an important role in the reaction, and that the use of an appropriate base can make the reaction proceed readily to give stereodefined cyclopropyl-substituted alkenes in good to high yield.