This study explores the potential pedagogical benefits and challenges of incorporating ChatGPT, an advanced AI language model, into English as a Foreign Language (EFL) writing exercises, focusing on students’ perceptions. Conducted with 20 Vietnamese EFL students from two higher education institutions, the research employed a qualitative approach through semi-structured interviews. The theoretical frameworks of Constructivist Learning Theory and the Technological Acceptance Model (TAM) underpinned the analysis. The findings revealed several benefits of using ChatGPT, including enhanced engagement in writing exercises, improved writing skills, increased learner autonomy, and exposure to diverse languageuses. These benefits align with constructivist principles of active learning and TAM’s emphasis on perceived usefulness and ease of use. However, challenges were also noted, including an over-reliance on technology, concerns about the accuracy and appropriateness of the AI-generated content, limitations in creative expression, and ethical and privacy issues. These challenges highlight the need for balanced integration of AI in language learning and careful consideration of its pedagogical implications. Given the limitations of the study, such as the small and homogenous sample size and the sole use of qualitative methods, future research is recommended to include a larger, more diverse population and to employ quantitative methods for a more comprehensive understanding. Comparative studies on different AI tools and their long-term effects, as well as investigations into the perspectives of other stakeholders, are also suggested.This research underscores the transformative potential and challenges of integrating ChatGPT in EFL writing, advocating for a nuanced approach to harnessing AI in education.