The present study set out to investigate how Turkish teachers of English as a foreign language (EFL) use the first language (L1) in their classrooms. In particular, at procedural level, it examined the functions of L1 in three Turkish EFL classrooms in a secondary school in Turkey. At conceptual level, it attempted to explore the teachers' perspectives on the use of L1. Three secondary school EFL teachers were involved in the study. Data consisted of 15 lesson-hour audio-recorded observations and semi-structured interviews. The findings indicated that L1 in the three teachers' classroom discourse served three major functions: The teachers either used L1 to communicate the content of the lesson (Academic) or to regulate classroom interactions and proceedings efficiently (Managerial). They also made use of L1 when they shifted the focus of the lesson to efforts of rapport construction (Social/Cultural). In addition, there seemed to be multiple interacting factors affecting the teachers' decisions of when and why they use L1. (C) 2014 Elsevier Ltd. All rights reserved.