The use of Learning Management System (LMS) is widespread in academic institutions across worldwide as technology integration in education keeps evolving. This study aims at investigating students' acceptance of using LMS for online testing. Additionally, the study seeks to thoroughly examine the reasons that lead to their acceptance of this educational technology for online testing. Using a mixed-methods approach, the study collects data from 245 university students in the Mekong Delta, Vietnam, using both quantitative questionnaires and semi-structured interviews. The theoretical framework, the Technology Acceptance Model (TAM), directs the examination of the major reasons influencing students' acceptance of LMS for online assessments. Findings from this research indicate that participating students approve of using LMS for online testing due to several reasons. The implications of the study extend to educators, administrators, providing valuable insights for optimizing the integration of LMS into educational practices and fostering a positive online learning environment. [For the complete proceedings, see ED672804.]