Drawing on the literature reviews of this special issue of the International Journal of Clinical and Experimental Hypnosis (2000), this article summarizes the evidence for the effectiveness of hypnosis as an empirically supported clinical intervention. As a whole, the clinical research to date generally substantiates the claim that hypnotic procedures can ameliorate some psychological and medical conditions, as judged against the Chambless and Hollon methodological guidelines. In many cases, these clinical procedures can also be quite cost-effective. It is probable that with some key empirical refinement a number of other hypnosis treatment protocols will have sufficient empirical documentation to be considered "well-established." However, it is noted that the Chambless and Hollon guidelines are not particularly well-suited for assessing hypnosis' impact when used adjunctly with other interventions. The article concludes with recommendations regarding the efficacy questions that need to be more fully addressed empirically and offers methodological guidelines for researchers and practitioners.