Uterine leiomyoma is the most common female benign pelvic tumor, affecting 20-25% of women during their reproductive years. There is strong clinical evidence that these tumors are estrogen-dependent for their growth, as also supported by their clear regression after the menopause. Although large clinical trials have not yet been reported, according to the estrogen dependency of uterine fibroids, LHRH agonists have been shown to be effective in the treatment of these conditions because they produce a condition of temporary hypoestrogenism secondary to the specific hypogonadotrophinism. This study was designed to evaluate if specific binding sites for LHRH are present in human uterine leiomyomata, myometrium and endometrial tissue. These tissues were taken from the fresh operative specimens of 14 patients who had undergone total hysterectomy for uterine leiomyomata. The results of this study demonstrate the presence of a LHRH specific binding site in uterine leiomyomata in 26% of cases; this specific binding site is also present both in myometrium and in endometrial tissue in 71% of cases. Moreover our study shows, for the first time, the high specificity of binding between LHRH agonist (goserelin) and natural LHRH receptor. In accordance with our results, a direct effect of LHRH agonists on fibroid tissue can be stressed.