Women in the United States, and their physicians, are "rediscovering" intrauterine devices (IUDs). Two IUDs, the 10-year Copper T 380A (Paragard) and 1-year progesterone-releasing T (Progestasert) are currently marketed in this country. In contrast to previous perceptions, recent studies have provided reassurance regarding the safety of these effective and convenient contraceptives. We now recognize that IUDs do not increase salpingitis or infertility risks in long-term users. Likewise, we now better understand the mechanism of action of copper IUDs: both the inert plastic device as well as the copper contribute to a spermicidal effect, preventing fertilization. Finally, we now recognize that copper IUDs reduce a user's overall risk of ectopic pregnancy. For appropriately informed and selected candidates, IUDs represent a safe, effective, convenient, and low-cost contraceptive option.