A lot of research has focused on exploring reasons for and solutions to Asian students’ reticence in speaking. It is found that their unwillingness to speak is affected not only by the students themselves but also by the situations they are placed in. However, there is still space to explore how teachers use interaction strategies to enhance students’ speaking involvement, especially in Vietnam. This paper examines the relationship between teacher interaction strategies and student oral involvement. The data were collected via audio-recording and class observation. Five experienced teachers and their respective classes at a center for foreign languages were invited to participate in the study. The data were analyzed qualitatively based on the three interaction strategies proposed by Lee and Ng (2010). The findings show that three types of interaction strategies were used by the teachers in the classroom and had a positive effect on student oral involvement. The extent to which students are involved orally in response to these strategies was discrepant. More importantly, there are others elements related to pedagogical factors such as lesson objectives, task type, activities used, classroom management and the proficiency level of the students which were also identified to impact a teacher’s interaction strategy decision making
