The aim of this work is the assessment of landslide risk of the Volcanic Group of Santorini (Greece). The methodology followed was based on the application of multi-criteria analysis (Multicriteria Decision Analysis-MCDA) in a Geographical Information System (GIS) environment (ArcGIS 10.5). The original data was converted to digital form, georeferenced in the national coordinate system GGRS'87, and individual layers were processed through digitization. Furthermore, a geodatabase was created in order to enrich the spatial information with the requisite descriptive information. The above was necessary for further processing and analysis, which include the classification of factor's data, according to the specific requirements of the region. Model Builder, an ArcGIS tool, was used to produce a Model which resulted in individual maps for each thematic layer, in addition to providing local authorities with an easy-to-use adaptable tool for landslide susceptibility mapping. Finally, a ranking method was used to generate criterion values for every factor. Then, each factor was weighted according to the estimated significance for causing landslides and the final susceptibility map was produced, depicting vulnerable areas.