This article reviews research findings involving visual input in speech processing in the form of facial cues and co-speech gestures for second-language (L2) learners, and provides pedagogical implications for the teaching of listening and speaking. It traces the foundations of auditory-visual speech research and explores the role of a speaker's facial cues in L2 perception training and of gestural cues in listening comprehension. There is a strong role for pedagogy to maximize the salience of multimodal cues for L2 learners. Visible articulatory gestures that precede the acoustic signal and the preparation phase of a hand gesture that precedes the acoustic onset of a word provide a priming effect on perceivers' attention to signal upcoming information and facilitate processing, and visible gestures that co-occur with speech aid ongoing processing and comprehension. L2 learners benefit from an awareness of these visual cues and exposure to input.