The protection and preservation of good groundwater quality is of critical importance worldwide, nowadays. Increasing urbanization, economic development and agricultural activities, combined with limited precipitation contribute to the quantitative and qualitative degradation of groundwater resources, especially in the eastern Mediterranean region. For this purpose, a series of actions are implemented including groundwater vulnerability mapping that can depict prone to pollution aquifers which need protection and/or restoration measures. In this study, the efficiencof two well-known methodologies (COP and DRASTIC) for groundwater vulnerability and pollution risk mapping was assessed in the Sperchios river basin. The vulnerability and pollution risk maps of the two methodologies were spatially compared to each other and the observed similarities and differences were discussed and explained. The output of the study shows that in the particular geoenvironmental conditions DRASTIC method performs better than the COP, particularly in the lowland, porous media aquifer.