A B S T R A C TPolicy makers have to consider the sustainability perspective in strategic planning decisions. Identifyand measure the level of sustainability, through its three dimensions, is a priority. Therefore, the aim of this work is to present a new model, called GeoUmbriaSUIT, integrating Multicriteria Analysis and Geographic Information Systems, specifically developed for helping Decision Makers to take policy decisions about sustainability in planning. The model provides outputs which are easy to be understood by not experts; the evaluation path is traceable and transparent, thanks to back analysis.To better explain the potentiality of GeoUmbriaSUIT and its functioning, a case study about Malta is described. Our results showed that in four regions of Malta the best dimension was the environmental one, while only for two regions (Northern Harbour and Southern Harbour) respectively the economic and social dimensions obtained the best scores. The integration of MCDA-GIS resulted to be a useful tool for sustainability assessment.