The dynamics of brain activation reflecting attractiveness in humans are unclear. Among the different features affecting attractiveness of the female body, the waist-to-hip ratio (WHR) is considered to be crucial. To date, however, no event-related potential (ERP) study has addressed the question of its associated pattern of brain activation. We carried out two different experiments: (a) a behavioural study, to judge the level of attractiveness of female realistic models depicting 4 different WHRs (0.6, 0.7, 0.8, 0.9) with and without clothes; (b) an EEG paradigm, to record brain activity while participants (heterosexual men and women) viewed these same models. Behavioural results showed that WHRs of 0.7 were considered more attractive than the others. ERP analyses revealed a different pattern of activation for male and female viewers. The 0.7 ratio elicited greater positivity at the P1 level in male viewers but not females. Naked bodies increased the N190 in both groups and peaked earlier for the 0.7 ratio in the male viewers. Finally, the late positive component (LPC) was found to be greater in male than in female viewers and was globally more marked for naked bodies as well as WHRs of 0.7 in both groups of viewers. These results provide the first electrophysiological evidence of specific time periods linked to the processing of a body feature denoting attractiveness and therefore playing a role in mate choice.