This chapter investigates the integration of artificial intelligence (AI) tools. Specifically, ChatGPT can support personalized instruction in IELTS writing classes. This study investigates student performance and teacher perspectives in a real-world IELTS writing course to address the gap in current research on AI-assisted writing in test preparation contexts. A quasi-experimental design was used in an IELTS writing course at a language center in Can Tho, Vietnam, involving 32 students divided into control and experimental groups. Both groups received the same instruction, but only the experimental group used AI tools to support writing tasks. Pre- and post-test assessments showed that students using AI tools achieved higher improvements, particularly in grammar correction, vocabulary enhancement, and error reduction. Interviews with teachers before and after the course revealed an initial skepticism that shifted to cautious optimism. Teachers recognized the strengths of AI in providing immediate feedback and improving surface-level accuracy but expressed concerns about its limitations in supporting logical coherence and essay development. The findings highlight the importance of teacher mediation and suggest that AI should be used as a supplementary tool, not a replacement for instruction. The chapter concludes by offering practical strategies for ethical and effective integration of AI in writing classrooms, encouraging a balanced approach that combines technological support with human guidance in promoting personalized language learning.