A series of Macromolecular Design by Interchange of Xanthates (MADIX)-derived amphiphilic block copolymers exhibiting lower critical solution temperature behaviour was synthesized and evaluated as silicone oil-in-water emulsion co-stabilizers. It was demonstrated that the cloud point of the block copolymer is mainly controlled by the chemical composition of the N-isopropylacrylamide-based hydrophilic block. The reversible stabilization and destabilization phenomena of the silicone emulsions occurred at a temperature equal to the cloud point of the block copolymer taken alone.