Background <p>Studies have shown that acute stress significantly impacts the selection of emotional stimuli. However, the extent to which acute stress affects the cognitive mechanisms underlying target enhancement and distractor suppression when selecting emotionally neutral stimuli remains unclear.</p> Methods <p>We explored this issue using the Maastricht Acute Stress Test (MAST), a visual search task, and event-related potential recordings. Eighty healthy adults participated in the experiment, which required them to search for a specific target while ignoring a color singleton distractor.</p> Results <p>The MAST successfully induced a stress response in the stress group, as indicated by higher levels of salivary cortisol, state anxiety, and negative emotion, as well as lower levels of positive emotion. Importantly, the stress group showed a significantly smaller N2pc in the lateral target with middle distractor displays than the control group. However, no significant differences in P_D were observed in the middle target with lateral distractor displays.</p> Conclusions <p>These results suggest that acute stress impairs target enhancement rather than distractor suppression during attentional selection. This impairment may be due to impaired prefrontal cortex function under acute stress. The present research provides new insight into how acute stress affects attention selection.</p> Trial registration <p>Not applicable. This study was conducted with healthy participants in a laboratory setting and does not meet the criteria for a clinical trial.</p>