Purpose: The main purpose of this study is aimed to estimate the mediating role of student engagement in the structural relationships between students' field of study choice, learning readiness and academic competence of undergraduate students in higher education. Design/methodology/approach: In the study process, a correlational design was employed. Data were collected from 419 participants who were selected through a simple random sampling technique. Structural equation modeling (SEM) was used to analyze the data. Findings: The study findings showed neither field of study choice nor learning readiness has a significant direct effect on student's academic competence. However, when student engagement, entered the relationships between "field of study choice and academic competence" as well as "learning readiness and academic competence", the indirect effects became significant. Both conditions, therefore, suggesting student engagement had a full mediation role in the structural relationship models. Originality/value: Based on the results, it can be concluded that student engagement is shown as one of the key variables used to comprehend how students develop competence in the teaching-learning process. Hence, teachers and academic administrators could use engagement as a strong instrument to optimize students' learning and academic competence to enhance their academic success.