This study aimed: 1) to compare the students’ English speaking ability before and after learning through the Engage- Study- Activate Method; 2) to compare the students’ self-efficacy toward English speaking ability before and after learning through the Engage- Study- Activate Method. The samples of this study were 28 grade 6/1 students who enrolled in English for Daily Life (EN 16201) in the second semester of academic year 2019 at Muangsurin School, in Surin province, Thailand. They were selected by cluster random sampling technique using the classrooms as sampling units. The research instruments were six lesson plans, the pre-test and post-test of speaking performance test, and self¬-efficacy questionnaire. The statistics used to analyze the collected data were mean, standard deviation, and t-test with the statistical significance set at .05 level. The findings were as follows: 1. the students’ English speaking ability after using the Engage- Study- Activate Method was higher than pre-test mean score with statistically significant difference at .01 level. 2. The students’ self-efficacy towards the Engage- Study- Activate Method to improve English speaking ability was higher than before learning in overall with statistical significance at .01 level.