Waist-to-hip ratio (WHR) is defined as a human secondary sexual trait, affecting the attractiveness and conveying information about reproductive and genetic potential. To date, no electrophysiological indices have been found related to this aspect. The main goal of our research was to investigate the behavioral and electrophysiological indices linked to WHRs in female body processing and their relation to perceived sexual attractiveness in a healthy adult heterosexual population. We performed a behavioral rating task on attractiveness with 42 heterosexual subjects (20 males and 22 females) using 200 real female body pictures, seen from a back or front view, presenting 4 different WHRs (0.6, 0.7, 0.8 and 0.9). Consecutively we performed two 128-­‐channel EEG experiments with 18 heterosexual participants (9 males and 9 females). We presented WHR models from a front view with 4 different WHRs and scrambled pictures in a body decision task, in which participants were asked to reply manually to the targets (body or scrambled). In an attractiveness decision task, subjects looked at front views of female bodies with 2 different WHRs (0.7 and 0.9) while they rated them as “attractive” or “unattractive”. WHR variation modulated the reaction times and the behavioral ratings of the subjects, which showed a gradient of preference with bodies with medium (0.7) WHRs having the highest and bodies with high (0.9) WHRs having the lowest scores. WHR variation also affected P1 and N1 ERP components in terms of amplitude but not in terms of latency, and this modulation depended on the gender of the subject, the parameters of the task, and if the stimuli were targeted or untargeted. Our results also showed potential electrical sources behind some differences in the ERPs, revealing the possible role of the left middle frontal gyrus as a neural signature of WHR processing in men. Limitations of this study are discussed and perspectives for further analyses and future studies are suggested.