EFL high school students’ low level of participation is reported as a problem commonly found in English speaking classes. This study aims to investigate high school students’ perceptions of suggestions for promoting students’ participation in English speaking classes. Questionnaires and interviews were employed as data collection instruments of the study. 206 EFL high school students from three grades in a high school in the Mekong Delta, Vietnam responded to the questionnaire and then 6 of them participated in the semi-structured interview sessions. The results strongly endorsed that “promote students’ self-confidence”, “make learning tasks stimulating and the way teachers present tasks”, “establish a supportive and caring relationship”, and “create a pleasant classroom climate” were significant strategies promoting students’ participation. The results of the study are expected to contribute to the comprehension of teachers’ strategies to enhance students’ participation in English speaking classes.