In hilly places, constructing and building forest roads requires a variety of economic and environmental criteria. To develop a solution that minimize construction, maintenance, and adverse environmental effects, road management must take into account as many alternative alignment options as they can. The idea of this research was to plan the network of forest roads in the Periyar Tiger Reserve's mountainous region using Geographic Information Systems (GIS) based on Multi-Criteria Decision Analysis (MCDA). These techniques were applied using the study area's slope, aspect, Elevation, NDVI, drainage and susceptibility to landslides datasets. In addition, the road network created using the GIS-MCDA approach was contrasted with the existing road networks. The key elements that affect the road network in the research area were found, and the necessary maps were produced and categorized. The maps were graded using MCDA to determine the weight of both useful aspects as the next step in determining the significance and role of the aforementioned elements in the cost of road building. Second, using the Arc GIS 10.4 weighted overlay analysis tool, a forest potential map for road building was created by overlaying the weighted maps of the influencing elements. Thirdly, the competence of a map was divided into Six categories: very high, high, moderate, low, very low and Restricted roading Suitability. Finally, using a weighted overlay method to combine the road network and road planning potential map, the existing road network was analyzed. The findings of this study indicated that the majority of existing roads were located in high and moderate road Suitability. A small percentage was located in low road Suitability, which can be taken into account for alignment. These results suggested that the design of forest road planning in hilly areas can be more precisely accomplished using the multi-criteria evaluation method. Similar method as used in this study can be applied to other forested sites.