During the time of the COVID-19 pandemic, online teaching was implemented by teachers in almost all education areas, and various technological tools were also employed to improve teachers' online teaching effectiveness. Based on this, the current qualitative case study aims to explore chemistry teachers' experience during online teaching in Malaysian secondary schools according to the data collected by interviewing five teachers. The findings show that student-centered teaching strategies, such as project-based and game-based pedagogy, may be well implemented in online environments by teachers, especially during the pandemic session. In addition, educational changes caused by the pandemic have provided new development opportunities for teachers' teaching, in which teachers ponder how to better use the existing high-tech tools to serve their teaching practice and improve their students' engagement and learning enthusiasm. Discussions and recommendations for future researchers are also provided at the end of the research.