The intrauterine device (IUD) is the oldest long acting reversible contraceptive (LARC) method. There remain widespread barriers to its general acceptance, although some have been overcome, others remain. These stem from a lack of understanding of uterine anatomy and physiology. Uterine measuring techniques did not become popular, probably because of the extra effort required prior to IUD insertion. Unfortunately the information they provided regarding IUD design was also not heeded. In some countries varying sizes of other IUDs (second generation) are now available. The third generation hormonal carrying IUDs have also reduced barriers by lowering side effects and producing added health benefits. Fourth generation IUDs will provide added health benefits in addition to contraception and should further reduce barriers to IUD use. Most remaining IUD barriers are due to provider perceptions. Most are based on psychological, moral and religious prejudices. These should not be allowed to interfere with the provision of LARC methods of contraception. There are also acceptor barriers which can be modified by providing education about the method. The use of the IUD as a LARC method is increasing in many developed and developing countries. New technology should help propel the IUD into a more mainstream contraceptive.