ERPs were recorded to investigate the processing of the appraisal of conscious and unconscious affective stimuli as being sexual using a backward masking paradigm. Twenty heterosexual participants between 18 and 35 years old had to discriminate whether bodies were naked or dressed in a supraliminal presentation (260 ms) and in a subliminal presentation (16 ms). The results showed that during the supraliminal presentation and the subliminal presentation, the amplitude of the N190 component was significantly larger for the images of sexual characteristics versus dressed bodies over occipito-temporal electrodes. Through a segmentation procedure, a specific topographical microstate associated with the N190 component was found, though it didn't provide further information on the processing of sexual characteristics. The neural generators responsible for the processing of sexual characteristics were located at the occipito-temporal lobe as well as the amygdala. However, there were no significant differences between images of sexual characteristics of bodies and dressed bodies for the early visual P1 component over occipito-temporal electrodes.