In this paper, we propose an improved spec- trophotometric method that can be used to quan- titate zinc directly, based on the colour reaction between the metal ion and xylenol orange in the presence of surfactant cationic cetylpyridinium chloride. The method saves time and effort, as well as many chemicals. Different variables that affect the reaction of xylenol orange with zinc in micellar solutions as well as a detailed description of procedures are presented. The method pro- posed has been successfully applied to the deter- mination of zinc contained in dermal ointment.