Cognitive models of posttraumatic stress disorder (PTSD) highlight characteristics of trauma memories, such as disorganisation, as key mechanisms in the aetiology of the disorder. However, studies investigating trauma memory in youth have provided inconsistent findings. Research has highlighted that PTSD in youth may be accompanied by difficulties in neurocognitive functioning, potentially impacting ability to recall the trauma memory. The present study sought to investigate both trauma memory characteristics and neurocognitive functioning in youth aged 8–17 years. Youths exposed to single-event trauma, with (N = 29, Mage = 13.6, 21 female) and without (N = 40, Mage = 13.3, 21 female) a diagnosis of PTSD, completed self-report measures of trauma memory, a narrative memory task and a set of neurocognitive tests two to six months post-trauma. A group of non trauma-exposed youths (N = 36, Mage = 13.9, 27 female) were compared on narrative and neurocognitive tasks. Results indicated that trauma memories in youth with, versus without, PTSD were more sensory-laden, temporally disrupted, difficult to verbally access, and formed a more ‘central’ part of their identity. Greater differences were observed for self-reported memory characteristics compared to narrative characteristics. No between group differences in neurocognitive function were observed. Self-reported trauma memory characteristics highlight an important factor in the aetiology of PTSD. The observed lack of significant differences in neurocognitive ability potentially suggests that cognitive factors represent a more relevant treatment target than neurocognitive factors in single-event PTSD. Further research to understand the cognitive factors represented by self-reported trauma memory characteristics is recommended.