Laser flash photolysis was used to investigate the formation of radical ions produced in the quenching of the pyrene-N,N'-dimethylaniline exciplex by reverse micelles made with benzylhexadecyldimethylammonium chloride (BHDC) dispersed in benzene or chlorobenzene. The radical ion quantum yields, φion, were determined as a function of BHDC concentration and the amount of water dispersed. They were strongly dependent on the composition of the media. The charge separation was more effective in the BHDC-benzene than in the BHDC-chlorobenzene system. The results are discussed in terms of the properties of the micellar interface and the fast exchange of material produced by collisions between reverse micelles.