Hypnotherapy is claimed to be effective in treatment of psychosomatic disorders. A meta-analysis was conducted with 21 randomized, controlled clinical studies to evaluate efficacy of hypnosis in psychosomatic disorders. Studies compared patients exclusively treated with hypnotherapy to untreated controls. Studies providing adjunctive standard medical care in either treatment condition were also admitted. Hypnotherapy was categorized into classic (n = 9), mixed form (n = 5), and modern (n = 3). Results showed the weighted mean effect size for 21 studies was d(+) = .61 (p = .0000). ANOVA revealed significant differences between classic, mixed, and modern hypnosis. Regression of outcome on treatment dose failed to show a significant relationship. Numerical values for correlation between suggestibility and outcome were only reported in three studies (mean r = .31). The meta-analysis clearly indicates hypnotherapy is highly effective in treatment of psychosomatic disorders.