The investigations have been directed to technology development in the usage of natural resources as a result of increase in the world energy demand associated with environmental factors. It has also sparked interest in the scientific community to take a closer look at the energy conversion devices and develop the new techniques to better utilise the existing limited sources. Geothermal resources have a great importance for the energy potential in Turkey. Exergy of a system is the capability of doing work and exergy values of geothermal resources are the strongest criterion for determining the system efficiency. In this study, geothermal resources in Turkey have been classified based on specific exergy rates (SER). The computed results of exergy analysis can be used as a tool for evaluating the characteristics of resources, and the optimum application area of geothermal resources can also be defined.