This thesis investigated the understanding of academic literacies in Vietnamese higher education from the viewpoint of students and lecturers in programmes using English as a medium of instruction at a business university in Vietnam. Through semi-structured interviews and analysis of institutional documents, the study aimed to explore how academic literacies were understood, applied, and experienced, as well as their influence on teaching and learning practices. Drawing upon Communities of Practice as a theoretical framework, the findings revealed that academic literacies are a new concept in the Vietnamese context and encompass various aspects, including disciplinary knowledge, English language proficiency, academic reading and writing, critical thinking, and essential skills. Notably, the concept of conducting research emerged as specific to students within these programmes. The study highlighted the influence of students' and lecturers' perceptions of academic literacies on teaching and learning practices, emphasising the importance of fostering self-study, independent thinking, and collaborative learning within academic communities. Based on the findings, the study proposed a conceptualisation of academic literacies and a model to support students' transition into higher education. The model emphasised the need for targeted support in academic reading, writing, critical thinking, and research methodology, involving collaboration among academic stakeholders and timely interventions to facilitate students' academic success. These findings contributed to the understanding of academic literacies in the Vietnamese context and offered practical insights for educational practice and policy.