False beliefs and memories can affect people's attitudes, at least in the short term. But can they produce real changes in behavior? This study explored whether falsely suggesting to subjects that they had experienced a food-related event in their childhood would lead to a change in their behavior shortly after the suggestion and up to 4 months later. We falsely suggested to 180 subjects that, as children, they had gotten ill after eating egg salad. Results showed that, after this manipulation, a significant minority of subjects came to believe they had experienced this childhood event even though they had initially denied having experienced it. This newfound autobiographical belief was accompanied by the intent to avoid egg salad, and also by significantly reduced consumption of egg-salad sandwiches, both immediately and 4 months after the false suggestion. The false suggestion of a childhood event can lead to persistent false beliefs that have lasting behavioral consequences.