In communication a great deal of meaning is exchanged through body language, including gaze, posture, hand gestures and body movements. Body language is largely culture-specific, and rests, for its comprehension, on people's sharing socio-cultural and linguistic norms. In cross-cultural communication, L2 speakers' use of body language may convey meaning that is not understood or misinterpreted by the interlocutors, affecting the pragmatics of communication. In spite of its importance for cross-cultural communication, body language is neglected in ESL/EFL teaching. This paper argues that the study of body language should be integrated in the syllabus of ESL/EFL teaching and learning. This is done by: 1) reviewing literature showing the tight connection between language, speech and gestures and the problems that might arise in cross-cultural communication when speakers use and interpret body language according to different conventions; 2) reporting the data from two pilot studies showing that L2 learners transfer L1 gestures to the L2 and that these are not understood by native L2 speakers; 3) reporting an experience teaching body language in an ESL/EFL classroom. The paper suggests that in multicultural ESL/EFL classes teaching body language should be aimed primarily at raising the students' awareness of the differences existing across cultures.