The process of consciously trying to avoid certain thoughts is referred to as thought suppression. Experimental research has documented that thought suppression may have paradoxical effects in that it leads to an increased frequency of the to-be-suppressed thought intruding consciousness. It has also been claimed that suppression has disruptive effect on episodic memory (i.e., a less paradoxical effect). The present article critically evaluates studies on the paradoxical and less paradoxical effects of thought suppression. More specifically, the issue of whether thought suppression plays a causative role in the development of various psychopathological symptoms is addressed. While laboratory studies have come up with highly consistent findings about the paradoxical effects of thought suppression, there is, as yet, little reason to believe that such effects are implicated in the etiology of obsessions, phobias, or other psychopathological conditions. Relatively little work has been done on the alleged memory effects of thought suppression. The studies that have examined this issue have found mixed results. Accordingly, the case for the amnestic power of thought suppression is weak. Alternative explanations and competing theories are discussed, and it is concluded that research concerned with the psychopathological consequences of thought suppression would benefit from development of better taxonomies of intrusive thinking and cognitive avoidance strategies.