In representational momentum (RM), the final position of a moving target is mislocalized in the direction of motion. Here, the effect of a concurrent sound on visual RM was demonstrated. A visual stimulus moved horizontally and disappeared at unpredictable positions. A complex tone without any motion cues was presented continuously from the beginning of the visual motion. As compared with a silent condition, the RM magnitude increased when the sound lasted longer than and decreased when it did not last as long as the visual motion. However, the RM was unchanged when a brief complex tone was presented before or after the target disappeared (Experiment 2) or when the onset of the long-lasting sound was not synchronized with that of the visual motion (Experiments 3 and 4). These findings suggest that visual motion representation can be modulated by a sound if the visual motion information is firmly associated with the auditory information.