Although it is well established that stress can disrupt complex cognitive functions, relatively little is known about how it influences visual processing, especially in terms of visual selective attention. In the current study, we used highly aversive images, taken from the International Affective Picture System, to induce acute, low-intensity stress while participants performed a visual discrimination task. Consistent with prior research, we found that anticipation of aversive stimuli increased overall amplitude of the N170, suggesting an increase in early sensory gain. More importantly, we found that stress disrupted visual selective attention. While in no-stress blocks, the amplitude of the face-sensitive N170 was higher when participants attended to faces rather than scenes in face–scene overlay images; this effect was absent under stress. This was because of an increase in N170 amplitude in the scene-attend condition under stress. We interpret these findings as suggesting that even low-intensity acute stress can impair participants' ability to filter out task-irrelevant information. We discuss our findings in relation to how even brief exposure to low-intensity stress may adversely impact both healthy and clinical populations.