In January 2018, a young male of Didelphis aurita (Wied-Neuwied, 1826), the Brazilian common opossum, was admitted for veterinary evaluation at the Recovery Clinic of Wild Animals of Estácio de Sá University, CRAS, in Rio de Janeiro, Brazil, due to the presence of a partially duplicated right hind limb. After x-ray evaluation, polymelia associated with syndactyly was diagnosed. The images revealed the following alterations on the right limb: single femur with increased diameter, two tibiae, two fibulae and absence of hallux. The observed malformations were restricted to the hind right limb, which remains functional. This is the first report of such anomalies in an individual of Didelphis aurita.