In this paper, deposition, electrical, optical and structural characterizations of SnO2-ZnO transparent conducting binary-binary systems with various compositions have been investigated. Firstly, the n-type SnO2 thin films are deposited using a hydro-alcoholic solution by spray pyrolysis technique. Then, certain amounts of zinc chloride (anhydrous) have been added to the initial solution, in order to prepare the SnO2-ZnO transparent conducting binary-binary system with various chemical compositions. The SnO2-ZnO polycrystalline thin films were deposited at T-S = 480degreesC with a Zn-content [Zn/(Sn + Zn)] atomic ratio of 0-30 at.% in films. The effect of increasing Zn-content on electrical, optical and structural properties of SnO2-ZnO films has been studied. The results of X-ray diffraction and Scanning electron microscopy analysis, Hall effect experiment and resistivity measurement of films in the high Zn-concentration indicate the association of both SnO2 and ZnO phases in thin film structure. In addition, for a given Zn-content atomic ratio (20.7 at.% in film), both electrical conductivity and carrier concentration increased sharply. (C) 2003 Elsevier Science B.V. All rights reserved.