Analogical reasoning has long been believed to play a central role in mathematics learning and problem solving (see Genter, Holyoak, & Kokinov, 2001); however, little is known about how analogy is used in everyday instructional contexts. This article examines analogies produced in naturally occurring U.S. mathematics lessons to explore patterns between analogy generation and instructional context. One hundred and three analogies were identified in a random sample of 25 eighth-grade mathematics classrooms videotaped as part of the Third International Mathematics and Science Study (see Stigler et al., 1999). Qualitative codes were used to gather quantitative data about the set of analogies, and emergent patterns considered. Specifically, the study examines patterns of teacher-student participation, analogy source and target construction, and contexts for analogy production. These data suggest that teachers regularly use analogy as instructional mechanisms to teach concepts and procedures, differentially generating sources to match the content goal of the analogy. The source and target construction is also related to whether the analogy is in response to students' needs for help. Teachers typically maintain control of each analogy by producing the majority of the comparison, though students are regularly involved in the components of the analogy that require minimal analogical thinking.