Background: There is increasing theoretical, clinical and research evidence for the role of trauma memory in the aetiology of acute pathological stress responses in adults. However, research into the phenomenology of trauma memories in young people is currently scarce. Methods: This study compared the nature of trauma narratives to narratives of unpleasant non-traumatic events in young people (aged 8-17) who sought emergency medical attention following an assault or road traffic accident. Data were collected within 2-4 weeks of the index event. Symptom severity was assessed by child self-report and face-to-face diagnostic interviews. Comparisons of narrative indices were made between those children with acute stress disorder (ASD) and those without ASD. Results: Among participants (n = 50), those with ASD (38%) had significantly elevated levels of disorganisation in their trauma narrative, compared both to trauma-exposed controls and to their unpleasant comparative narrative. This effect was not accounted for by age. Regardless of ASD diagnostic status, trauma narratives had significantly higher sensory content and significantly lower positive emotion content compared to the unpleasant comparative narrative. These effects were not significant when age was included as a covariate. Acute symptom severity was significantly predicted by the level of disorganisation in the trauma narrative and the child's cognitive appraisals of the event. Conclusions: These data provide the first empirical evidence that disorganisation is not only directly linked to symptom severity, but also specific to the trauma memory. In addition, it provides support for the adaptation of adult cognitive models to acute pathological stress reactions in children and adolescents.