Many abstract bipolar concepts are usually represented by metaphors on vertical dimensions (e.g. positive-up, negative-down). However, several studies have found an asymmetry in the way in which individuals process bipolar dimensions, with +polarities being stronger than -polarities. The current research focused on moral metaphors on a vertical dimension (e.g. moral-up and immoral-down) and examined the asymmetric representation of moral and immoral concepts. The first experiment showed a distinct metaphorical association between morality and vertical space, consistent with earlier research. The second experiment showed that moral and immoral words are processed differently depending on whether they are used as metaphorically congruent or incongruent vertical cues. 'Moral-up' association modulated the amplitudes of the N1, P2, and late positive-going potential during the processing of moral words, whereas the 'immoral-down' association only modulated the amplitudes of the late positive-going potential induced during the processing of immoral words. These results suggest that asymmetry in the processing of vertically represented morality metaphors is reflected in the time course of the representation of these bipolar concepts, with the 'moral-up' association having an earlier effect than the 'immoral-down' association.