The purpose of this study was to examine how TCIT influences Korean children’s disruptive behavior in school as well as teachers interactions with their students. Ten preschool classes were randomly assigned to either the experimental group which received the TCIT training program or the waitlist control group which did not. The TCIT program was conducted in 12 sessions, twice a week for one hour. The DPICS were diagnosed before and after the TCIT to test for any changes in the quality of the teachers’ interactions. To assess children’s behavioral problems as perceived by their teachers, researchers executed the SESBI-R. The results of this study showed that teachers who had received TCIT had significantly increased positive interactions and decreased negative interactions with their students. Furthermore, teachers with TCIT training reported a meaningful decline in disruptive classroom behavior. This study provides evidence for TCIT supporting teacher self-efficacy and fighting teacher burnout and demonstrates the effective use of TCIT at the preschool level in an experimental setting in Korea for the first time