The nucleophiiic addition of cyanide ion to the rosaniline hydrochloride (RH) carbocations in aqueous media is catalysed by the cationic micelles of CTAB and is inhibited by anionic micelles of SDS. The reactions follow pseudo-first order kinetics. The rate constant depends on surfactant concentration. The micellar data have been quantitatively analysed by Positive Cooperativity model of enzyme catalysis. The added counterions show inhibitory effects on the overall catalysis.