Abstract- Self efficacy can influence a person's choice of action. Likewise, individual students of primary school age are able to brush their teeth with the correct procedure. This study aims to examine the effect of self-efficacy on students' actions to brush their teeth properly (with the right tool, on time and in the right way). The research method was a quasi-experimental research design with a randomized control group pretest-posttest design. In this research design, the subjects were divided into two groups, namely the treatment group and the control group, all of which would be carried out pretest and posttest. The population of this study were all Grade 5 Elementary School students in the working area of Puskesmas Pegandan Kota Semarang. The intervention carried out was assisting in teeth brushing use a control card when brushing teeth at home for 10 days, after being given education using booklets to both groups. Data analysis was performed using the Wilcoxon Signed Ranks Test to determine differences in self-efficacy and student actions before and after the intervention in the intervention group and t test in the control group. Meanwhile, the correlation test between self-efficacy and action used the nonparametric correlation test. The results showed that there were differences in self-efficacy and respondent actions between before and after the intervention (p <0.0001). There is a relationship between self-efficacy and respondent's actions in the intervention group (p <0.005). In the control group, there was no relationship between self-efficacy and respondent actions (p = 0.089).