This study aimed to determine the classroom engagement levels of university students studying English Preparatory Classes, and the factors affecting their engagement in the classes. In the study, survey method, which is one of the qualitative research methods, was employed. The population of the study consisted of students selected from Bilecik Seyh Edebali University's "Optional English Preparatory Classes" during 2016-2017 academic year. The sample of the study consisted of 67 students selected from the population through random sampling. Mixed method was used to obtain the data, with quantitative data obtained from 67 students, and qualitative data obtained from nine students determined by criterion sampling method. In the study, the "Classroom Engagement Scale for University Students" developed by Eryılmaz (2014), and the "Learning Climate Questionnaire" adapted to Turkish language by Kanadlı and Bağçeci (2016) were both employed. Qualitative data were collected through open-ended questions prepared by the researchers, and content analysis was performed in its analysis. As a result of the study, it was determined that the emotional and cognitive engagement levels of the students were at an appropriate level, and that behavioral engagement was at a slightly appropriate level. The students stated that personal factors, characteristics of the program, implementation of the program and factors related to teacher behavior affected their engagement in English language preparatory classes.