The long-term benefits of cognitive behaviour therapy (CBT) for trauma survivors with acute stress disorder were investigated by assessing patients 3 years after treatment. Civilian trauma survivors (n=87) were randomly allocated to six sessions of CBT, CBT combined with hypnosis, or supportive counselling (SC), 69 completed treatment, and 53 were assessed 2 years post-treatment for post-traumatic stress disorder (PTSD) with the Clinician-Administered PTSD Scale. In terms of treatment completers, 2 CBT patients (10%), 4 CBT/hypnosis patients (22%), and 10 SC patients (63%) met PTSD criteria at 2-years follow-up. Intent-to-treat analyses indicated that 12 CBT patients (36%), 14 CBT/hypnosis patients (46%), and 16 SC patients (67%) met PTSD criteria at 2-year follow-up. Patients who received CBT and CBT/hypnosis reported less re-experiencing and less avoidance symptoms than patients who received SC. These findings point to the long-term benefits of early provision of CBT in the initial month after trauma.