The intrauterine device (IUD), one of the most effective and most common methods of reversible contraception, is used by millions of women worldwide. Although various studies indicate the benefits of its use as a contraceptive method, the greatest concern regarding IUDs is the potential risk for infection. The presence of the IUD gives a solid surface for bacterial attachment and biofilm formation. Infections due to biofilm formation are chronic and difficult to resolve. However, women should be screened and treated for asymptomatic vaginal or cervical infections before IUD insertion. Based on the data in the literature and the data in study conducted in Croatia, it can be concluded that IUD users are at increased risk for development of infection. Treatment strategies in Croatia should take into consideration that Escherichia coli and Ureaplasma urealyticum are dominant causative agents. We conclude that guidelines for the use of IUD in Croatia are a necessity.