An experiment investigating the hypothesis that trying to suppress a thought will lead to an immediate and/or delayed increase in its occurrence is reported. Normal subjects listened to a taped story and then verbalized their stream of consciousness during two consecutive time periods. During the first period, one group (suppression) were asked not to think about the tape while two other groups (controls) were asked to think about anything or think about anything including the tape. During the second period, all three groups were instructed to think about anything. Results from the first period failed to support the immediate enhancement hypothesis as the suppression group reported less thoughts about the tape than the controls. However, results from the second period supported the delayed (rebound) hypothesis as subjects who had previously suppressed reported more thoughts about the tape than subjects who had not. The theoretical, methodological, and clinical implications of these results are discussed.