Protecting our natural heritage is important in today’s world. As with any destination and its specific places, prior to any planning for potential geotourism destinations, a thorough assessment should be conducted to determine the status and value of natural heritage sites/geosites. This assessment should provide a clear picture about future activities for further development and management of geotourism in these sites. In this applied study, the descriptive-analytical method was used for data analysis toward synthesis of a Geosite Assessment Model by combining the existing models into an integrated model in order to assess the natural heritage sites/geosites conditions in Sistan and Baluchestan Province as a potential geotourism destination in Iran. Four methods including Kubalíková, Fassoulas, Comanescu, and GAM/M-GAM were used to evaluate 42 valuable natural heritage sites/geosites in the province. Based on the implementation and scoring values obtained from the synthesis method, the best geoheritage sites for educational and tourism activities are Lut Desert, Mangrove Forest, Taftan Peak, and Hamoun Lake, respectively. This study proves that the province sites are attractive and suitable for geotourism destination. However, upgrading the province sites for local and even regional and international geotourism activities requires improving environmental conditions, reducing ecological risks, and providing tourism infrastructure.