Previous research showed that a bitter taste in the mouth is able to enhance hostile response tendencies to social rejection. The present event-related potential (ERP) study sought to investigate neuronal components of this effect. We presented 52 participants (39 women and 13 men; mean age = 23.3 years) with images of facial expressions signaling social rejection (angry, disgusted) or no rejection (happy, neural), whereas they either experienced a bitter aftertaste (bitter group [BG]: n = 26) or rinsed their mouth with water (control group [CG]: n = 26). The BG rated the aftertaste as extremely intense and disgusting and showed a decreased parietal P200 to all facial expressions, as well as a lowered parietal P300 to cues of nonrejection. The bitter intervention neither influenced the affective ratings for the images nor self-reported hostility. In conclusion, the ERP findings indicated that bitterness first reduced visual attention to social cues in general (P200) and then specifically to cues of nonrejection (P300). Bitterness was not associated with increased sensitivity to disgust/anger signaled by others neither on a neuronal nor self-report level.