Content-based instruction, a method of foreign language instruction in which the main topics being taught come from the regular content-area curriculum, is used in elementary school foreign language programs to integrate language development with content-area learning. This goal is accomplished by providing activities in which the learner's experiences are a vehicle for both language learning and content-area learning through which the learning of higher-level cognitive skills is possible. The guide to content-area teaching for teachers of foreign languages in the elementary schools (FLES) offers background and a rationale for content-based instruction, planning guidelines, and sample lesson plans in mathematics, science, and social studies. The discussion of background and rationale reviews current thinking and some research on the topic and gives some examples of the benefits of content-based instruction in mathematics, science, social studies, art, music, and physical education. The section on planning for content-based instruction presents specific guidelines for identifying appropriate curriculum, coordinating with content-classroom teachers, identifying instructional materials, and planning the lesson. Areas of concern are also examined. The sample lessons, designed to be carried out entirely in the target language, address a variety of grade levels. Additional activities are also suggested. A brief bibliography is appended. (MSE)