ChatGPT usage has gained popularity in education. ChatGPT is an AI that can produce human-like text and has implications for teaching. This study explored eight Indonesian English teachers’ lived experiences in leveraging ChatGPT in their teaching preparation through phenomenological study. Participants’ perceptions, emotions, pedagogical activities, decision-making, and teaching transformations were explicated from their lived experiences through one-on-one in-depth interviews and analyzed through thematic analysis. The findings showed teachers’ varied perceptions, with some considered it as a useful tool to generate ideas and materials, while aware of its limitations in human-like understanding. Further, teachers felt both excitement and concern towards ChatGPT. The integration practice resulted in improved teaching planning while retaining the quality after thoughtful adaptations. Additionally, ChatGPT helped teachers provide a better learning approach and contextualized learning. Significantly, as ChatGPT becomes more widely accessible, further research is required to guide teachers on wiser utilisation.