Smart teaching is an essential skill for teachers to effectively transform their classrooms into active learning environments. However, teachers need to have specific abilities to apply the smart teaching approach which comprised of pedagogy, technology, and classroom management. This research was conducted based on the Khon Kaen University Smart Learning Project which has been implementing in junior high schools in Thailand to enhance students' competencies in active learning environments for five years. The research aimed to study the smart teaching abilities of teachers in the project which composed of: (1) creating the student's expected learning outcomes; (2) course contents management; (3) application of teaching technique and technology; and (4) organization of learning activities in a digital learning environment. A survey method was done using questionnaires sent to teachers of grades 7-9 who were teaching in three subjects; science, mathematics and English language, of which 1,226 were responded. Data was analyzed by using descriptive statistics. The results of smart teaching abilities of teachers based on their backgrounds: teaching subjects (science, mathematics, and English language), teaching classes (grades 7, 8, and 9), and teaching experiences (1-10 years, 11-20 years, and >20 years) were presented. It was found that overall, mathematics teachers have higher smart teaching abilities than those of science and English teachers. Teachers of grade 7 and teachers with 1-10 years of teaching experiences were found to have higher smart teaching abilities that the others in their dependent variables. This research provides an understanding of the situation which will be useful for the teachers' skills development. In addition, the information is useful for junior high school teachers and administrators to use as a guideline for enhancing smart teaching ability in the context of new learning environments.