Emotion regulation is pivotal in human interactions and well-being. Modulating one's emotional state is intricately linked with psychological, behavioral, and physiological responses. Extensive research has explored how individuals with varying attachment orientations manage emotions, predominantly through self-report measures and behavioral assessments. However, the influence of attachment orientations on temporal electrophysiological dynamics during emotion regulation tasks remains underexplored. Here, 90 adults' EEG brain activity was recorded while they engaged in tasks of attending to, reappraising, or suppressing emotions elicited by unpleasant images. Their attachment orientations were assessed using the Experiences in Close Relationships-12 (ECR-12) questionnaire to explore the association between Late Positive Potential (LPP) and attachment anxiety and avoidance amidst the deployment of emotion regulation strategies. Using Linear Mixed-Effects Model analysis, our results revealed a lower amplitude of the LPP during cognitive reappraisal, suggesting the efficacy of this strategy in diminishing emotional intensity. Moreover, higher attachment anxiety exhibited increased LPP amplitude during both Reappraisal and Suppression, as well as during the negative natural condition, indicating heightened emotional responses. This study provides novel insights into the relationship between attachment orientations and emotion regulation, as evidenced by EEG-based measurements of the LPP. The findings indicate that individuals with higher attachment anxiety display distinct electrophysiological responses, particularly in emotional scenarios.