The levonorgestrel-releasing intrauterine device (IUD) (Mirena) is a frequently used and effective method of contraception, with a Pearl index of 0.1. The ectopic pregnancy rate is 0.02 per 100 woman-years. Special attention is needed in situations where pregnancy is detected with a levonorgestrel-releasing IUD in situ, because almost two thirds of these pregnancies are ectopic. We describe one of these rare cases of ectopic pregnancy in a woman aged 37 years, who was admitted to hospital with abdominal pain and vaginal bleeding.