This paper seeks to explore a web-based teaching activity designed for technological pedagogical content knowledge (TPCK) development in pre-service history teacher education in Turkey. The study is conducted by action research methodology. Using a project-based learning (PBL) approach, the designed activity aims to provide the necessary background knowledge to support student-teachers for their use of the wikis as a teaching tool in history education. The results show that the PBL activity engaging student-teachers as authors in Wikipedia reveals as an effective and motivating tool for initiating them to web authoring. Wikipedia authoring activity has been also fairly influential in terms of improving the student-teachers' historical knowledge. However, the acquisitions reported by participants do not display the same effectiveness in terms of the pedagogical knowledge and TPCK. The paper discusses the probable reasons of outcomes and the proper measures to be taken in order to improve an efficiency model. The results support the idea arguing that an effective TPCK development in pre-service teacher education requires systematic engagement of student-teachers in rich teaching experiences within the real teaching contexts. (Contains 3 tables and 1 figure.)