Sixty-one participants from the community participated in a randomised controlled trial of group debriefing to assess the effect of this intervention upon memory for a stressful event. Participants were randomly allocated to one of three groups: debriefing; debriefing with an experimenter confederate present (who supplied three pieces of misinformation to the group regarding the stressful event); and a no-treatment control. All groups were shown a very stressful video and were again reviewed after 1 month. Members of the debriefing group where a confederate provided misinformation were more likely to recall this misinformation as fact than members of the other two groups. The debriefing group was also more accurate in their recall of peripheral content than the confederate group. Across all groups, participants were found to be more accurate at central rather than peripheral recall yet more confident for incorrect memories of the video than correct memories.