Vilsmeier-Haack Reaction with Acetanilides afforded formyl derivatives with DMF/SOCl2. The reactions obeyed pseudo first order kinetics. There was a dramatic rate enhancement when micelle-forming surfactants such as cetyl tri methyl ammonium bromide (CTAB), sodium dodecyl sulphate (SDS) and triton-X 100 (Tx) were used as catalysts. Rate (kΨ) versus [Surfactant or CD] profiles was generally wavy in nature with all the surfactant systems. The results in micellar media were interpreted using Pizkiewicz’s cooperativity model