The article describes features of trauma memories in post-traumatic stress disorder (PTSD), including characteristics of unintentional re-experiencing symptoms and intentional recall of trauma narratives. Reexperiencing symptoms are usually sensory impressions and emotional responses from the trauma that appear to lack a time perspective and a context. The vast majority of intrusive memories can be interpreted as re-experiencing of warning signals, i.e., stimuli that signalled the onset of the trauma or of moments when the meaning of the event changed for the worse. Triggers of re-experiencing symptoms include stimuli that have perceptual similarity to cues accompanying the traumatic event. Intentional recall of the trauma in PTSD may be characterised by confusion about temporal order, and difficulty in accessing important details, both of which contribute to problematic appraisals. Recall tends to be disjointed. When patients with PTSD deliberately recall the worst moments of the trauma, they often do not access other relevant (usually subsequent) information that would correct impressions/predictions made at the time. A theoretical analysis of re-experiencing symptoms and their triggers is offered, and implications for treatment are discussed. These include the need to actively incorporate updating information ("I know now ...") into the worst moments of the trauma memory, and to train patients to discriminate between the stimuli that were present during the trauma ("then") and the innocuous triggers of re-experiencing symptoms ("now").