Polymorphism of the mu-opioid receptor gene (OPRM1) has been shown to reduce both the sensory and affective dimensions of pain by binding at opioid receptors. The activation of brain regions associated with the processing sensory intensity decreased linearly in relation to opioid analgesic drug concentrations, which was significantly less pronounced in OPRM1 118G carriers. It suggests that the OPRM1 might be associated to the somatosensory intensity also in the multisensory processing. By this perspective, we investigated the role of OPRM1 118A＞G for multisensory processing using the paradigm of the visuotactile congruency effect. The participants grasped an expanded polystyrene cube with two vibration motors and 2 LEDs by the thumb and forefinger of their left hand. The task was to judge the location of the tactile stimuli. The visuotactile congruency effect was the RT difference between the congruent (e.g. both visual and tactile stimuli were presented at the forefinger) and incongruent condition. In the results, the 118A carriers showed the greater congruency effect than the 118A non carrier, which indicated the group difference by polymorphism of OPRM1 on visuotactile congruency effect. This suggests that there is the inherited difference on the visuotactile integration processing.