IntroductionComplications of copper load intrauterine devices, including ectopic pregnancies are well reported. Rates of ectopic pregnancy are 0.6 to 1.1% per year. However, the levonorgestrel intrauterine device has been described as more protective against ectopic pregnancies due to the addition of the hormone levonorgestrel. The hormone released from the intrauterine device causes some systemic effects, but local effects such as glandular atrophy and stromal decidualization, in addition to foreign body reaction, are dominant. Few case reports have described ampullary ectopic pregnancies. However, we report, for the first time, a major complication of levonorgestrel intrauterine device: a cornual pregnancy.Case presentationA 36-year-old Caucasian nulliparous woman presented with complaints of progressive nausea, abdominal pain and irregular vaginal bleeding for 2 months. For 3 years, she had been using a levonorgestrel intrauterine device. A two-dimensional transvaginal sonogram noted a sac situated external to the endometrial cavity in the right cornua of the uterus with an empty uterus. She was successfully treated with chemotherapy.ConclusionMany complications have been described, including ectopic pregnancies, using copper intrauterine devices. The levonorgestrel-releasing intrauterine system is a particularly good choice for adolescents because of associated non-contraceptive benefits such as decreased menstrual bleeding, dysmenorrhea and pain associated with endometriosis [1]. Yet a cornual pregnancy following the use of a levonorgestrel intrauterine device is a complication which, to our knowledge, has not been described before. Physicians prescribing this type of intrauterine device should be aware of this rare event.