Background <p>Body Dysmorphic Disorder (BDD) is a psychiatric condition characterized by obsessive preoccupation with perceived physical flaws, often accompanied by emotional dysregulation and attentional biases. Despite increasing clinical recognition, the neurophysiological and attentional mechanisms underlying BDD remain poorly understood.</p> Methods <p>This study employed a multimodal experimental design to compare individuals with BDD (<i>n</i> = 27) and healthy controls (<i>n</i> = 27). Participants completed standardized psychometric assessments and were exposed to emotionally valenced facial and body-related images while undergoing electroencephalography (EEG), galvanic skin response (GSR), and eye-tracking. Group-by-valence interactions were analyzed using mixed-model ANOVAs.</p> Results <p>The BDD group showed significantly higher depression, anxiety, body image disturbance, and suppression scores, alongside reduced cognitive reappraisal and self-efficacy. EEG analyses revealed increased N170 amplitudes, attenuated P300 amplitudes, and greater right-sided frontal alpha asymmetry, suggesting early hypervigilance, reduced evaluative processing, and affective withdrawal. GSR data indicated heightened sympathetic arousal and delayed physiological recovery. Eye-tracking data descriptively indicated gender-specific attentional patterns within the BDD group, with females allocating greater visual attention to facial and lower-body regions and males showing increased fixation on muscular upper-body features; such patterns were not observed in the control group.</p> Conclusion <p>BDD is associated with dysregulated multisystem responses to appearance-related stimuli, characterized by neural hyperreactivity, impaired cognitive–emotional regulation, and gender-related patterns of visual attention. These findings support the utility of integrating psychophysiological and attentional markers into individualized assessment and intervention strategies for BDD.</p> Clinical trial number <p>Not applicable.</p>