The copper intrauterine device (IUD) is a safe, long-acting, and effective method of contraception that is under-utilized in many countries, including Malawi. A unique cohort of women who had enrolled in a trial of postpartum IUD use one year earlier gave insights into reasons for using, discontinuing, or not using the IUD. We conducted in-depth interviews with 18 women one year after they participated in a pilot study of a randomized controlled trial of postpartum IUD insertion, and 10 of their male partners. Women and their partners expressed a strong desire for family planning, and perceived numerous benefits of the IUD. However, fear of the IUD was common among successful users and non-users alike. This fear arose from rumours from friends and neighbors who were non-users. How women and their partners responded to this fear affected IUD adoption and continuation. Key themes included (1) Trust in information received from health care providers versus rumours from community members; (2) Partner involvement in IUD decision-making; and (3) Experience with side effects from short-term hormonal contraceptive methods. Broad community education about the IUD’s benefits and safety, and proactive counseling to address couples’ specific fears, may be needed to increase uptake of the method.