Gn-RH analogues have been recently employed for the treatment of oestrogen-dependent benign gynaecological disorders, such as uterine myomata, endometriosis or metrorrhagia. They induce a "pharmacological castration", inducing a marked reduction of serum oestrogen levels. They proved more effective than other drugs used up to now in the medical treatment of these benign gynaecological diseases. Thus they were initially employed in every case. Later it became clear that Gn-RH analogues need a selective indication. The authors herein report their series of 70 patients with benign gynaecological disorders (45 uterine fibroids, 10 endometriosis, 15 metrorrhagia), treated with a Gn-RH analogue depot for 2-3 months preoperatively. They evaluated the efficacy of the treatment in the group with uterine fibroids in terms of disappearance of metrorrhagia, better haemoglobin level in anaemic patients, reduction of fibroids size allowing for a simpler and less extensive surgery (vaginal surgery, myomectomy, hysteroscopic resection). The authors discuss those cases when preoperative treatment with Gn-RH analogues is not indicated, or should be employed only under careful surveillance (in the preparation of multiple myomectomies, big submucosal myomas). In the group of 10 patients with endometriosis we observed the disappearance of pelvic pain and dyspareunia, whereas the size of endometriomas was only minimally reduced. The authors discuss the usefulness of this treatment in case of patients with endometriosis grade I or II (minimal or mild), with desire of children. In the group of 15 perimenopausal patients with metrorrhagia, 10 became amenorrhoic after termination of treatment, thus avoiding surgery. The major benefit for the other 5 patients was a better haemoglobin level at the time of surgery.