EFL course books reflect a characteristic of contemporary Western society: the strong presence of images. Considering that social, professional and academic practices demand knowledge of images and ability to produce them, it is important to understand how the study of images can become an integral part of language study. Authors such as Kress and van Leeuwen (2000) and Unsworth (2004) argue for the need for visual literacy as visual communication has become more prominent in EFL course books. One of the most evident visual elements is the photograph. Photographs are versatile images that can be used in legal data, in historic, medical and scientific documentation, as well as in EFL course books. This dissertation investigates the functions of photographs in the activities suggested in an EFL course book, the negotiation of meanings in photographs, and the social relations between the producer of the image and the observer. This research uses a qualitative analysis of images following Kress and van Leeuwen`s (2000) The Grammar of Visual Design, which is based on the theory of Systemic Functional Grammar by Halliday (1994, 2000). The analysis of the course book shows that photographs illustrate arguments, bridge the students` and the teacher`s world with the real world outside the classroom, and bring meanings into the course book. It also points out the importance of conducting more research on multimodality in EFL course books and developing new methodologies for visual analysis.