Already in 1909 methods of an intrauterine contraception were indicated in Germany. Their practical use was intiated twenty years later by Ernst Graefenberg. Further development almost exclusively takes place in the USA, whereas the major part of basic investigations has been done. The introduction of copper bearing IUD's undoubtedly increased the safety of intrauterine contraception. Investigations concerning the morphology of the endometrial contact area (f.e. by SEM) and the evaluation of certain biochemical facts associated with the release of copper ions, lead to hypotheses of the mode of action. A randomized comparative study of CuT 200 verus Lippes Loop D demonstrates similar pregnancy rates with both types of IUD, but a moderate advantage of the CuT 200 in regard of the expulsion rate and the removal rates due to bleeding and/or pains. The author stresses that it might be medically indicated to terminate pregnancy when a woman has conceived in spite of a copper bearing IUD in situ. His statement is in correspondence to the recommendations of the Population Council, but nevertheless, this problem as yet is far of being solved unanimously. Most complications associated with the IUD are due to incorrect insertion. It is therefore postulated to insert the IUD menstrually, maintaining strictly sterile conditions, a non-deformed uterus being hooked on a bullet forceps. As already anticipated by Ludwig Fraenkel a careful insertion should be done by experienced doctors only, this fact counteracting the widespread use of this contraceptive method to be in the second place as compared to hormonal contraception.