Manual co-speech gestures can facilitate language comprehension, but do they influence language comprehension in simultaneous interpreters, and if so, is this influence modulated by simultaneous interpreting (SI) and/or by interpreting experience? In a picture-matching task, 24 professional interpreters and 24 professional translators were exposed to utterances accompanied by semantically matching representational gestures, semantically unrelated pragmatic gestures, or no gestures while viewing passively (interpreters and translators) or during SI (interpreters only). During passive viewing, both groups were faster with semantically related than with semantically unrelated gestures. During SI, interpreters showed the same result. The results suggest that language comprehension is sensitive to the semantic relationship between speech and gesture, and facilitated when speech and gestures are semantically linked. This sensitivity is not modulated by SI or interpreting experience. Thus, despite simultaneous interpreters’ extreme language use, multimodal language processing facilitates comprehension in SI the same way as in all other language processing.