This article provides a perspective on the use of the levonorgestrel-releasing intrauterine system as a contraceptive method and as therapy in different situations, as well as presenting the corresponding controversies and unresolved issues. All studies have reported high contraceptive efficacy, an improvement in menstrual blood loss in women with idiopathic menorrhagia, menorrhagia due to thrombophilic diseases and fibroids, and excellent endometrial protection during postmenopausal estrogen therapy. Moreover, the device is able to reduce pelvic pain and clysmenorrhea as well as improve the staging of enclometriosis and adenomyosis, and to control, albeit partially, enclometrial hyperplasia. The expectation is that in years to come the number of hysterectomies and female sterilizations will fall due to increased use of the device, including use by patients with enclometriosis and HIV-positive women. It would also be desirable to develop a smaller device for postmenopausal women and nulligraviclas.