Academic writing, especially research article abstract writing, is still unfamiliar to many Vietnamese students. This study examines thematic choices and thematic development in 10 research article abstracts written by Vietnamese business administration students and compares them with 10 abstracts written by professional authors and published in accredited journals. The study focuses on topical, textual and interpersonal Themes and three patterns of thematic development, namely constant, linear and split Rheme patterns. The results show that the two groups share some similarities in their use of Themes and thematic development. However, some differences can be seen in clause structure and Theme choices. Vietnamese students tend to use simple clauses, unmarked Themes and nominal groups more frequently, while professional writers use a wider range of clause and Theme structures. This might be because students have limited English competence and are less familiar with the abstract genre. Based on these findings, some implications for teaching academic writing in the Vietnamese tertiary context are discussed.