The facial-width-to-height ratio (FWHR) measures the distance between the left and right cheekbones and divides it with the height between the brow ridge and the upper lip area. The FWHR has been proposed as a predictor of aggressive behavior, with larger FWHRs in males reportedly being perceived as more aggressive. Recent studies have utilized the late positive potential (LPP) to examine the electrophysiological correlates of FWHR. However, these studies have exclusively used male faces as stimuli, leaving the effect of the gender of the stimuli unexplored. The present study investigated how the combination of gender, FWHR, and threatening facial expressions influences the LPP response. Twenty-three participants were recruited for this study. The study used computer generated faces that varied across three variables: gender (male/female), FWHR (high/low), and expression (angry/neutral). The faces were displayed to participants while EEG was recorded to measure LPP amplitudes. Significant LPP modulations were observed for facial expressions (i.e., angry vs. neutral) but not for the FWHR or gender. These results may be attributed to the small sample size, the fact that FWHR was manipulated solely by adjusting cheekbone width, or the challenges in accurately distinguishing the gender of the faces. Future research should aim to create more distinct facial features to better explore potential gender effects.