PROMETHEE is a well known multicriteria decision support method which gives insight into the preference structure of a whole set of alternatives. The retrieved preference information is used to give the partial or complete preorder of the available alternatives which makes PROMETHEE a well suited decision support tool if a ranking of available alternatives is desired. A relatively low degree of mathematical complexity makes PROMETHEE an attractive method for all non experts involved in a decision process. This paper discusses the integration of PROMETHEE in a GIS. It will be shown how the combination of a sophisticated decision support methodology with powerful spatial analysis and visualisation capabilities can be applied to evaluating decision alternatives that are made up of regular or irregular shaped zones of raster cells. Deterministic as well as stochastic PROMETHEE approaches are considered and general recommendations on the use of stochastic simulation methods are given. Moreover, a framework is presented which facilitates the application of the proposed approaches.