The intrauterine contraceptive device is an effective, safe and convenient contraceptive method. Its use in less developed countries has been limited by the increase in menstrual blood loss, an important issue in populations with a high prevalence of anaemia. The levonorgestrel releasing IUD (LNg IUD) is the first device which is at the same time highly effective, long-lasting and reduces the blood loss during menstruation. This device was tested in 200 volunteers in Santo Domingo, Dominican Republic and in 381 in Campinas, Brazil. The cumulative pregnancy rate was 0 up to 7 years of use. The reduced bleeding was confirmed, and ferritin concentration among long-term users of the LNg IUD was significantly higher than among copper IUD users and controls using no contraception. Mean levonorgestrel plasma levels remained above 100 pg/ml until the seventh year of use. Endometrial histology showed mainly a marked reduction in epithelial growth, with variable signs of decidualization of the stroma. The most important reason for discontinuation in the two centres was amenorrhea, with cumulative rates of 10 and 15, respectively. This device should be very well accepted and will have a clear niche among reversible contraceptives, when available.