The reasoning is a concept that can be used explicitly or implicitly in different scientific disciplines and in different fields. Therefore, it is thought that studies conducted on reasoning will contribute directly and indirectly to many areas in many aspects. In general, although the concepts of reasoning and thinking are used interchangeably, reasoning is considered to be a more systematic and normative form of thinking. As an interdisciplinary concept, reasoning is an important term for both educational sciences and the related literature. The aim of this study is to investigate academic dissertations related with the concept of reasoning prepared in Turkey. Master's and doctoral theses from 1998 to 2017 prepared via using qualitative or quantitative research methods, the aims and themes of which are compatible with the content of this study, is included in this study. The data were collected by document analysis technique and analyzed by content analysis. As a result of the study, it was concluded that reasoning in the dissertations was focused as cognitive variable and investigated especially in science and mathematics. As a result of the study, although studies in the field of social sciences address the reasoning skills in terms of sociological variables, it was seen that the reasoning was examined as an isolated variable in terms of a sociological variables rather than being a sociological phenomenon investigated in terms of sociological phenomena. In the light of the findings, it was concluded that conducting studies involving reasoning skills and its relationship with thinking skills is an important necessity for the literature. As a result of the research, it has been suggested that reasoning skills should be examined in a more a broad perspective and in terms of an interdisciplinary point of view.