The solubilization of lindane by nonionic polyoxyethylene glycol surfactants has been studied in micellar solution, as well as in Winsor I and Winsor III microemulsions. The maximum of solubilization was determined when a saturated Lindane solution was in equilibrium with solid lindane. At this saturation point, the interfacial molar ratio lambda(max) of the solute to the surfactant was determined, taking into account the amount of lindane solubilized in oil. We first studied the evolution of the maximum excess solubilization lambda(max) as a function of surfactant volume fraction in water-C8E6 binary solutions. The excess solubilization was found to be constant between 0 and 50% in surfactant volume fraction. For higher volume fractions, lambda(max) increased with the surfactant concentration. This behavior is the result of a competition between water and lindane to be solubilized by the surfactant film. We also observed a decrease of the clouding temperature for the water-C8E6 system when Lindane is solubilized. We have evidenced a linear decreasing of lambda(max) with the reduced temperature (T-C(L) - T)/T-C(L) where T-C(L) is the cloud temperature for the saturated system. By comparison with results obtained with ternary microemulsions for two different curvatures, we have observed a strong dependence of lambda(max) on the average curvature of the surfactant film. The excess solubilization is maximum for the bicontinuous balanced structure obtained in the Winsor III case, where fluctuations produce the most stable structure versus the amount of added solute located in the surfactant film. When only excess oil is present (Winsor I), the o/w droplets at the emulsification failure boundary show an intermediate value of the maximum solubilization power.