Although a substantial amount of professional literature argues for the potential benefits of content-based instruction, limited research exists on how this type of instruction actually is appropriated, understood, and carried out in practice by foreign language teachers. This study examines the role of two sixth grade Spanish teachers' discursive practices in content-based instruction, the goals of instruction, and the students' proficiency. Through classroom observations, discourse analysis, teacher interviews, and student writing assessments, this study shows the significance of teacher talk in engaging students in learning both language and content, an overarching goal of content-based instruction. Several implications for instruction in content-based instruction programs and the professional development of teachers emerge from this study. (Contains 4 tables and 4 notes.)