The aim of the study was to examine postgraduate theses on epistemological beliefs in science education in Türkiye. Data collected included the publication years, researcher genders, universities, disciplines, aims, methods, sample/study groups, time allocated to the research, and data collection tools. The thematic content analysis method was used in the study. The data were obtained from the doctoral and master's thesis published until 2022 (including 2022) inclusive held at the CoHE National Thesis Centre. Access was gained to 149 theses dealing with the subject of epistemological beliefs in science education. The theses in the study were classified with reference to the matrix prepared by Ormanci, Çepni, Deveci and Aydin. The data obtained were analysed using content and descriptive analysis methods. The majority of the theses aimed to investigate the effect of a certain learning-teaching method on epistemological beliefs and the relationship between epistemological beliefs and some variables. It was determined that scales and questionnaires were mostly used as data collection tools in the evaluation of epistemological beliefs. There is a need for studies on the effect of current science learning-teaching methods on the development of epistemological beliefs or the relationship between epistemological beliefs and 21st-century skills.