The behavior of a cyanine dye (3,3′-di-(gamma-sulfopropyl)-4,5,4′,5′-dibenzo-9-ethylthiacarbocyanine betaine pyridinium salt) was studied in AOT/water/hexane reverse micelles over a wide range of W at various concentrations of the dye, AOT, and reverse micelles. The processes occurring during the formation of the AOT/water/hexane micellar solution were studied in detail. It has been shown that, before the formation of the stable microemulsion, the dye aggregation processes occur by virtue of the interaction of the dye with the AOT anion. The amount of J-aggregates is proportional to the logarithm of the ratio of the amount of AOT molecules to the amount of dye molecules. The time behavior of J-aggregates after the formation of a micellar structure depends on the concentration of reverse micelles, thereby indicating an important role of intermicellar exchange.