Several studies have examined the lack of or the insufficient preparation of K-12 educators to work in intercultural and bilingual (IBE) schools in Chile, but little is known about the preparation of educators to teach in IBE preschools. Even less is known about teachers' perceptions of their own preparation. This work contributes to a growing body of literature that examines the experiences and practice of second language teachers in Indigenous language education settings from a sociocultural perspective. This qualitative case study focuses on teachers' perceptions of their preparation to teach Mapudungun, the language of the Mapuche people, in urban IBE preschools in Chile. Three research questions guide this study: What are teachers' perceptions of their needs regarding their preparation to teach Mapudungun in urban IBE preschools? What are the current challenges that teachers face teaching Mapudungun in urban IBE preschools? Which experiences fostered their ability to teach Mapudungun? The findings of this study have implications for the incorporation of more complex notions of Indigenous language learning that are linked directly to Mapuche culture and its sociopolitical context, as well as the inclusion of teachers' experiential knowledge in the preparation of teachers for work in IBE schools.