A susceptibility indexing method was developed based oil vulnerability and quality indices. The contamination Susceptibility index (SI) at a given location was calculated by taking file product Of the Vulnerability index (VI) and the quality index (QI): SI = VI x QI. This method incorporates both hydrogeological and hydrochemical data for a comprehensive index mapping. The DRASTIC index methodology was used for the hydrogeological data evaluations. The quality index calculation procedure based oil a water quality classification scheme was introduced to evaluate hydrochemical data. The suggested susceptibility indexing method was applied to the Kucuk Menderes river basin located in western Turkey. The susceptibility index map shows both hydrogeological and hydrochemical data related to the contamination problem including areas that should be taken into consideration during Water management planning. The index map indicates that the most susceptible groundwater is located along the river channel between Kiraz and Tire towns, in the Selcuk area and along the Fertek stream channel to the north of Torbah town. file results indicate that the incorporation of both hydrogeological and hydrochemical datasets enables more realistic evaluations than those of an individual dataset to estimate the groundwater contamination Susceptibility of an aquifer. The numerical procedure applied Could be extended further by including other parameters Such as retardation, potential contaminant Sources, etc. that affect the water quality ill it given basin. (C) 2007 Elsevier Ltd. All rights reserved.