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.