Code switching is a common phenomenon that results from the bilingual quality of a language speaker. In the educational context, code switching is frequently found in an EFL classroom of which the teacher is a non-native speaker. It is considered as one of the strategies to facilitate students to learn English more effectively. However, a number of research studies investigating EFL classroom discourse found various reasons of the use of code switching, ranging from the familiarity of the context to the teacher\u27s language proficiency. The present research gears toward investigating code-switching practiced by an EFL teacher in Indonesia and the rationale behind that practice. Taking case study method, this qualitative study employs observation and semi-structured interview to gather the data. An English teacher in one vocational school in Indonesia was chosen to be the participant of the research. The research shows that, as a bilingual, the teacher practiced code-switching both in educational context and non-educational context, inter-sententially and intra-sententially. In the classroom context, inter-sentential code switching was practiced deliberately to serve as exposures for students. Meanwhile, intra-sentential code switching was oftentime not a deliberate action, but rather a force of habit of the English teacher as a bilingual
