This thesis investigates the critical thinking dispositions of undergraduate students at an English medium foundation university in Türkiye. It examines the critical thinking dispositions of students enrolled in a first year English composition course and whether their critical thinking dispositions differ according to gender, age, high school attended, attendance of an English preparatory program, and CGPA and course grade previously received in the first semester English composition course, as well as whether there is a relationship between critical thinking dispositions and CGPA. This study adopts a quantitative case research methodology, employing a combination of survey, causal-comparative and correlational design. To this end, the University of Florida/Engagement, Cognitive Maturity, Innovativeness instrument was yes to collect data. The major findings of the study include that the students report to have high moderate levels of critical thinking. They were not found to differ significantly according to the demographic factors with the exception of Cognitive Maturity, which differed significantly according to grade received in a first year English composition course. In addition, there was no significant correlation between critical thinking dispositions and CGPA.