Background: The purpose of this study was to investigate the relationship between attentional bias to threat and positive stimuli (i.e., facilitated attentional engagement, difficulty in attentional disengagement, and attentional avoidance) and event-related rumination, and to examine whether the latter mediated the relationship between attentional bias and posttraumatic stress symptoms (PTSS) and posttraumatic growth (PTG) in individuals with traumatic experiences. Methods: A total of 70 college students with traumatic experiences participated in the study. Attentional bias to threat and positive stimuli was measured by employing a spatial cueing task. Other variables were assessed using self-report measures including The Impact of Event-Related Scale-Revised, Event-Related Rumination Inventory, Post-traumatic Growth Inventory, and State-Trait Anxiety Inventory. Results: The results indicated that attentional avoidance was significantly associated with intrusive rumination, whereas none of the three aspects of attention bias was associated with deliberate rumination. Furthermore, attentional avoidance was related to increased intrusive rumination, which in turn, was associated with increased PTSS. Additionally, difficulty in attentional disengagement from threat stimuli was associated with finding new possibilities, one aspect of a PTG, even after controlling for the impact of deliberate rumination. Conclusions: The current results suggest that therapeutic interventions aimed at helping individuals not to avoid but accept their traumatic experience may be effective to overcome trauma and facilitate PTG among individuals with traumatic experiences.