The current study compared the effects of co-witness information on memory with more widely studied methods of encountering post-event information. Participants were shown a crime video and then exposed to both correct and incorrect post-event information about the video through one of four methods: (1) leading questions, (2) media report, (3) indirect co-witness information, or (4) co-witness discussion. There was also a control condition in which participants did not receive any post-event information. All participants were individually tested on their memories for the event 1 week later. Results suggest that co-witness information had a particularly strong influence on eyewitness memory, whether encountered through co-witness discussion or indirectly through a third party. That is, participants were more likely to report co-witness information than post-event information encountered through leading questions or a media report. Copyright © 2006 John Wiley & Sons, Ltd.