The usefulness of ultrasonography in IUD insertion and control, was evaluated. A follow up of IUD localization, placed at the end of puerperium and in non puerperal patients, was done. The copper T IUD 200 was used, and was placed in 50 patients. Ultrasonographic study was done right after IUD placement, at one month and at three months; uterine longitudinal sections, as well as transversal ones, for adequate localization of IUD; data were taken for control and followup. There were no IUD expulsion, pregnancy, or uterine perforation. Conclusions were: 1. Ultrasonography is useful for IUD control. 2. IUD placement at the hospital is adequate. 3. There were no complications. 4. Alterations produced by IUD insertion are more frequent during the first month, and very scarce at third month. 5. Dysmenorrhea was most frequent after IUD insertion. 6. Echosonographic control of IUD is the most accurate method in order to know its localization within the uterine cavity.