This research aims to analyses qualitative/mixed studies done between 2015 and 2019 on the knowledge of pre- and in-service science teachers in Turkey. For this meta-synthesis research, 10 Master's and 10 PhD theses, which are available in the archives of Higher Education Council National Thesis Centre, and two full-text articles published in the journals indexed in Google Scholar provided the data. In this research, the contents of these theses and articles are analyzed and synthesized in depth. Results revealed mixed method was mostly used in the studies selected, participants of the studies were mostly pre-service science teachers, the studies especially put more focus on the "technological pedagogical content knowledge" of the pre- and in-service science teachers, and the studies discussed mostly the knowledge levels of pre- and in-service science teachers. The findings of this meta-synthesis call for future qualitative studies which examine the growth of in-service science teachers' "technological pedagogical content knowledge" in particular as well as the level and development of other types of knowledge ("curriculum knowledge", "knowledge of learners and their characteristics", "knowledge of educational contexts", "knowledge of educational ends, purposes, and values and their philosophical and historical grounds", "technological knowledge", "technological content knowledge", and "technological pedagogical knowledge") of pre- and in-service science teachers.