This study is a qualitative and descriptive investigation of teacher gestures in EFL education. The specific aim is to describe the types, roles, and functions of gestures that are produced by native English speaking teachers in English as foreign language (EFL) classrooms in Japan by examining naturally occurring interactions. In addition to teacher gesture, I included some nonverbal behaviors such as suprasegmental features, nodding, and gaze direction so as to understand classroom interaction and communication in EFL classrooms. In order to accomplish these aims I employed a qualitative case study approach in five EFL classrooms at a university in an urban area in Japan. The primary data come from classroom interactions of a native English speaking teacher and his 26 students of one classroom over one semester that were analyzed through a microanalysis of videotapes of the naturalistic classroom interactions. In addition to videotapes, to better understand the interactions that occurred in the classroom, I gathered and analyzed observation notes from my perspective as a peripheral observer. I also collected retrospective stimulated video recall interview data from the teacher and some volunteer students for further analysis. Furthermore, in order to have wider understanding of multimodal foreign language (FL) classroom interactions, I observed four more EFL classes that were taught by two other native English speaking teachers at a university that was situated in a municipal capital in Japan as additional observations and a post-lesson survey with the teachers and students for additional analyses. My aim is not to seek causal explanation but to present plausible descriptions and interpretations of naturally occurring interactions in EFL classrooms. Analysis revealed that various types of teacher gesture were used by the teachers from five EFL classrooms. They were categorized into representational, referential, emphatic gestures, and emblems. The findings were further analyzed for the following functions: In EFL instruction, the teacher’s speech and gestures influence the transmission of knowledge and information as comprehension aids, classroom management, and students' affective states. All three teachers heavily relied on multimodal behaviors, primarily gestures. However, they not only used gestures, but also various nonverbal behaviors. The teachers selected a mode or a combination of modes according to their instructional purposes and personal styles such as giving knowledge and information, and giving directions. It was confirmed that the teachers presented visual input even when learners were not looking at them. The teachers' awareness of their gesture use differed individually. Whereas teacher 1 was not aware of his gesture production, Teacher 2 and Teacher 3 were conscious about their gesture uses and intentionally used certain types of gestures for pedagogy. Student interviews and survey suggested that the students perceived teachers’ gestures positively. Close analysis of the transcribed data suggests that multi-modes of communication including gesture serve to potentially enhance meaning-making in classroom interaction and communication. I assume that integration of these gestural functions of teacher gesture scaffold learning to some extent although the degree of its influence cannot be determined from this study. The teachers’ gestural and speech instruction might contribute to learning, in particular to multimodal semiotic meaning construction for the case of teacher gestures that function as comprehension aids, and that this kind of instruction definitely contributes to classroom management and atmosphere. Students reacted nonverbally to the teachers’ rich input in speech and gestural explanations, and followed the teachers’ speech and gestural directions. In addition, the classroom cohesion was promoted through the use of humor presented by bodily motions such as mimes and the use of students. This finding was confirmed by interview and survey results. This study contributes to the research on gesture in second and foreign language (L2 / FL) education, to the pedagogy of language education and subject matter education in the first language, and possibly to the larger body of research on gesture. / Language Arts