This article reports on two ethnographic studies that investigated student motivation in content-based ESL classrooms at a major U.S. university. The ESL population studied included immigrant and international students who were enrolled in the advanced level of the university’s ESL service courses. The ESL course materials consisted of videotaped academic lectures from university content courses (i.e., history, communication studies) and excerpts from authentic course texts as part of an academic skillsbased instructional sequence. Students were motivated through attention/ interest, relevance, confidence, and satisfaction, according to a motivational theory of instructional design. Classroom observations and interviews as well as examination of existing documents revealed that relevance of ESL materials and tasks was indeed motivating to a wide variety of students but that the other aspects of motivation were of equal if not greater importance. These findings lead to the belief that skills-based ESL courses in content areas of high general interest, in which instructors emphasize the relevance of materials and tasks, can do much to enhance student motivation and academic achievement in both ESL and content course work.