One way of providing students with the skills of 21st century is by involving students in the research process through teaching approaches such as inquiry-based learning. Project based learning is one of the teaching strategies based on inquiry-based learning. Project-Based Learning (PBL) is a student-driven, teacher-facilitated approach to learning. Geographic Information Systems (GIS) is an important development in geography and geography education both as a source and teaching method. It has also led to significant reforms in geographic education. Being a location-based system, GIS provides the opportunity for student-centered and standards-based education. GIS also encourages students and teachers to work on real life issues as project in their lessons. This research includes project-based GIS implementations done in high school geography lessons in Turkey. 15 students worked in three groups on the subjects of “The Analysis of Public Transport Network”, “The Analysis of School Districts” and “Creating 3D District Maps” in these project based GIS implementations. The implementation processes and their results were given in the book.