Mathematical thinking is closely related to students' success in solving mathematical problems. Local culture can be a resource to teach mathematical thinking skills. Nonetheless, a lot of teachers still struggle to help students develop their mathematical thinking abilities. This study aims to investigate the ethnomathematics approach applied by the teacher and the types of mathematical thinking that can be promoted through this approach. Case studies are used in this study with three junior high school mathematics teachers as key informants. They were selected based on their experience using the ethnomathematics approach in the classroom. Non-participant observation and in-depth interviews were used as data collection techniques. The findings show that different ethnomathematics approaches, with the use of different local cultures, will lead to different types of mathematical thinking skills. Based on these findings, conceptual and empirical implications are discussed for further recommendations for teachers and school stakeholders.