Although there is an increasing number of studies concentrating upon education, some researchers have revealed that most studies, including qualitative studies in education, have methodological issues. One of the most common mistakes and neglected issues in qualitative studies is not to ensure the trustworthiness of the research, which indeed is an important component for the rigor of the study. The main purpose of this study is to examine how researchers ensure the trustworthiness of Ph.D. dissertations in social studies education. Document analysis was employed in the study. I examined 197 Ph.D. dissertations belonging to years 2002 and 2020 as well as to the field of social studies education which were obtained from the National Dissertation Center of Turkish Higher Education Council. I used the deductive coding and analysis approach in order to examine dissertations. The study results revealed that no trustworthiness strategy was used or reported in nearly half of Ph.D. dissertations that were conducted in the field of social studies education. Researchers mostly preferred to use validity and reliability terms, which are highly criticized by some scholars as to the paradigm of qualitative orientations. Besides, while some trustworthiness strategies such as peer debriefing and external audit were mainly used, others such as negative case analysis and stepwise replication were not used or reported in any dissertation. Some recommendations were made considering the study results and discussions at the end of the study.