A methodology was developed about lead preconcentration in water samples that were addeddithizone as complexing agent, previously dissolved in the nonionic surfactant Triton X-114,until the formation of the critical micelle concentration and the cloud point temperature. Thecentrifuged system gave a precipitate with high concentrations of Pb (II) that was measuredby atomic absorption spectroscopy with flame (EAAF). The method has proved feasible tobe implemented as a method of preconcentration and analysis of Pb in aqueous samples withconcentrations less than 1 ppm. Several parameters were evaluated to obtain a percentagerecovery of 89.8%.