The present study was conducted to investigate the use of a flipped classroom in primary EFL classrooms in China. It is quasi-experimental research examming flipped and non-flipped classrooms in teaching English vowel letters in a primary school in China. Specifically, the researchers aimed at finding out the participating students' and teachers' perceptions towards the flipped classroom approach, whether it could be an approach for making students more engaged in their learning, and if it could enhance students' learning. Four classes of Primary 4 students (the flipped classroom approach was adopted in two classes and a traditional teacher-instructed method was used in the other two classes) were involved. Students in the two flipped classes learnt the English vowel letters by watching lecture videos before face-to-face lessons. On the other hand, students in the two non-flipped classes learnt the five vowel letters through a teacher-instructed approach in face-to-face lessons. Before the implementation of the study, a pre-test was administered to the students to find out their background knowledge. At the end of the study, a post-test was conducted to see if there was any gain in the scores obtained by the students. Qualitative data were also collected by eliciting opinions about the flipped classroom approach from the participating students and teachers. Implications for teaching and further research are drawn at the end of this paper.