Based on therapeutic studies revealing positive prognostic factors and on research findings revealing how trauma is processed, we developed the memory structuring intervention (MSI) in attempt to prevent posttraumatic stress disorder (PTSD). The MSI attempts to shift processing of traumatic memory from uncontrollable somatosensory and affective processes to more controlled linguistic and cognitive processes by providing patients organization, labeling, and causality. In a single-blind randomized-controlled pilot study, 17 traffic accident victims at risk for PTSD (heart rate >94 BPM) were assigned to two MSI or two supportive-listening control sessions. Three months later, MSI patients reported significantly less frequent intrusive, arousal, and total PTSD symptoms than controls. A replication study with a larger sample is underway.