In this preliminary study, we explored preservice and in‐service teachers’ sense of teaching self‐efficacy with a well‐established questionnaire and a newly adapted implicit measure of the self‐concept Single‐Target Implicit Association Test. Teaching self‐efficacy is an important construct when it comes to the handling of culturally heterogeneous classes. Hence, teaching self‐efficacy might also contribute to teachers’ motivational orientations regarding and beliefs about ethnic minority students. Using a quasi‐experimental design, we presented preservice and in‐service teachers with both the implicit and explicit measures of teaching self‐efficacy and found no differences due to teacher expertise on the explicit measure. However, the implicit measure revealed that preservice teachers had much weaker cognitive associations between the construct of teaching self‐efficacy and their self‐concepts. Motivational orientations regarding and beliefs about ethnic minority students showed substantial correlations with the explicit measure of teaching efficacy, while the implicit measure correlated with the self‐efficacy regarding the teaching of ethnic minority students, but only for in‐service teachers. The findings highlight the importance of the consideration of implicit and explicit teaching efficacy for the teaching in culturally heterogeneous classes. These first results should inspire researchers to consider both kinds of measures in future research, particularly when investigating the relationship between teaching self‐efficacy and teachers’ beliefs about and motivational orientations regarding the inclusion of ethnic minority students.