Objectives: The primary objective of this study was to assess the current intrauterine device (IUD) knowledge and counseling practices of US obstetrics and gynecology chief residents. The secondary objective was to evaluate the current IUD experience of obstetrics and gynecology residents. Methods: A Web-based survey about IUD knowledge and practices was sent to US obstetrics and gynecology residents in January 2010. An analysis of responses by postgraduate year was completed using descriptive statistics. Results: We received 699 surveys (36%) from a pool of 1922 residents in 96 different residency programs. A total of 654 respondents (94%) had placed an IUD during residency and 88% had received formal teaching about IUDs during residency. Only 53% of respondents knew that the copper IUD could be used for emergency contraception. Less than 65% of respondents would routinely recommend the IUD to adolescents or immediately after first trimester abortion. Conclusions: Many US obstetrics and gynecology residents lack knowledge about IUD benefits and do not counsel all eligible women to use IUDs. We should continue to evaluate our training and educational programs to ensure that women's health providers do not act as a barrier to IUD use.