Maras (Dolichotis patagonum) are monogamous and mate for life. A pregnant mara, 6.15 kg, died after forelimb amputation surgery at Seoul Zoo on February 28, 2009. In the bicornial uteri, two fetuses were found in each uterine horn. The placenta was chorioallantoic, hemochorial, discoidal and labyrinthic. The entrance of cervix had a deep fornix and no cervical folds were observed in the cervix. This report is the first about Patagonian mara and helpful for clinicians who deal currently or in the future with exotic pet animals.