Background/purpose: This study examined Vietnamese English majors' competence and perception of academic collocations to determine the need for targeted instruction. The research aimed to identify specific challenges these learners face in learning and using academic collocations in their writing. Methods: The study involved 199 Vietnamese English majors (60 males, 139 females) aged 20-21 who completed a test of 50 academic collocations selected from widely used academic texts and expert-curated lists. Six of the students participated in a follow-up interview that aimed to explore their perspectives on collocation usage and challenges in academic writing. Results: The test results revealed a significantly low understanding of academic collocations among the participants. Interview findings confirmed these challenges and highlighted specific difficulties Vietnamese learners encounter when using academic collocations. Conclusion: The findings underscore a pressing need for specialized instruction to address the specific challenges Vietnamese learners of English face in acquiring and correctly using academic collocations in their writing. Specifically, explicit instruction in academic collocations should be prioritized, integrating multiple teaching approaches. Educators are encouraged to incorporate targeted collocation exercises into writing curricula, provide contextualized practice, and implement strategies that enhance retention and practical application in academic writing.