There is an increasing recognition that emotion influences cognition. This is particularly clear in the domain of social cognition where the perception of social cues is most often a potent source of emotional arousal. One process likely to be influenced by emotion is the forming of face evaluations. Judgements of trustworthiness are particularly important due to the potential costs and benefits of the decision to rely upon another person. Face trustworthiness is modulated by one particular social cue, eye-gaze. In reaction time tasks, when faces gaze away from target objects, incongruently, responses are slower than when faces gaze towards target objects, congruently. Faces that consistently gaze incongruently are also judged less trustworthy than faces that consistently gaze congruently.! In six experiments, we investigated the role of emotion in the learning of trustworthiness from identity-contingent gaze-cues using event-related potentials (ERP) and facial electromyography (EMG), which are sensitive electrophysiological measures of emotion. We found that the learning of trust was paralleled by an increase in the emotionrelated late positive potential (LPP) to incongruent faces across blocks. These findings were further supported by EMG measurements, which showed that corrugator muscle activity related to negative embodied emotional states, was greater to incongruent faces in those participants who showed expected changes in trust ratings. Although effects of gaze-cues on trust were consistent, they were not modulated by extremes in initial trust or priming of emotions elicited by social exclusion. Effects appeared to be due to a special relationship between faces, gaze, emotion and trust as the effects of validity on liking ratings were much weaker or non-existent compared to trust despite evidence of similar emotion-related LPP ERP and EMG activity. The effects also did not generalise to non-social arrow cues. In sum, we conclude that emotion mediates the learning of trust from identity-contingent gaze-cues.