Different studies with different doses of mifepristone were released. The authors observe a decrease of leiomyomas volume. Based on this experience the present placebo controlled study has for objectives:-to confirm the efficacy of 10 mg oral mifepristone during 24 weeks in the volume decrease and in symptoms of leiomyomas, - to assess the safety of the treatment. The aim is to avoid or delay the hysterectomy of non menopausal patients. During the study patients will be evaluated with biological exams, clinical exams, echographies, medical interrogations and their diary cards.