Preschool education describes the education process of the child until primary school, and it is also within the scope of child bilingualism. This study examined the studies on bilingualism covering the preschool period in Turkey. The main statement of this study is that related postgraduate theses in different disciplines investigating the issue of bilingualism covering the preschool period are insufficient in the national literature in Turkey. This study aimed to analyze postgraduate theses between 2003 and 2022 registered in the Turkish Higher Education Institution (YÖK) database and to break down different variables. The main findings are that bilingualism studies are mostly concentrated on master's theses, they are not the subject of doctoral theses. Furthermore, education- and teaching-oriented theses are at the forefront and should be handled together with other disciplines. The model of the study is a qualitative case study, and the data of the study were obtained from theses on the website of YÖK. In the analysis of the data, the bibliometric technique is used, and statistics about the subject are created.