Herein a novel, elusive cyanotrifluoromethylthiolation of unactivated dialkyl-substituted alkynes is reported. Taking advantage of the intramolecular cyano migration strategy, the reaction proceeds stereoselectively to deliver E-olefinic products. A variety of tetrasubstituted trifluoromethylthiolated acrylonitriles are afforded in modest to good yields.