Background: Fundamental questions regarding the nature and function of attentional bias (AB) to threat in the etiology of posttraumatic stress disorder (PTSD) remain unanswered. We tested the temporal interplay between trauma exposure, dysregulated attentional processing of threatening information pre- and post-trauma, and the development of posttraumatic intrusions. Methods: Response time to trauma-related threat, trauma-unrelated threat, as well as to trauma-related but typically emotionally-neutral stimuli was assessed using the dot probe task before and one week after watching a violent movie scene that served as a trauma analogue. AB was analyzed as a dynamic process by means of a recently developed approach indexing momentary fluctuations of AB toward and away from emotional stimuli. Posttraumatic intrusions were measured daily over the week following analogue trauma exposure. Results: We found that key features of AB dynamics to trauma-related stimuli at post-, but not pre-, trauma exposure were associated with posttraumatic intrusions. Notably, these post-trauma exposure effects were specific to biased attentional processing of trauma-related but not threatening stimuli unrelated to the traumatic event. In line with a growing body of findings, pre- and post-trauma exposure traditional aggregated mean AB scores were not similarly associated with posttraumatic intrusions. Conclusions: We conclude that one mechanism through which trauma exposure may contribute to the development of PTSD is through its dysregulation of attentional processing of trauma event-related cues. Future work may focus on delineating the developmental course through which attentional dysregulation post-trauma and posttraumatic intrusions unfold and interact.