Uterine malformations and spontaneous triplet pregnancy are rare situations separately, and both are related to worse perinatal outcomes. In the 3 cases of combined triplet pregnancy and uterus didelphys previously published, at least 2 of the 3 fetuses died. Morbidity rates are also high. We report the case of a 24-year-old Caucasian woman with a uterus didelphys and two previous caesarean sections who carried a spontaneous triplet pregnancy. To our knowledge, this is the first case of a spontaneous triplet pregnancy in a uterus didelphys ever reported and the only one with uneventful perinatal outcome for all fetuses. Expectant management may be an alternative to embryo reduction to manage triplet pregnancies in a didelphys uterus, especially when this option is not considered. Nevertheless, there is not enough evidence to confirm which is the optimal management strategy, and more studies are needed.