Marsupials are members of the infraclass Marsupialia, a group of therian mammals. This infraclass consists of 7 orders: Didelphimorphia (opossums), Paucituberculata (shrew opossums), Microbiotheria (Monito del Monte), Dasyuromorphia (carnivorous marsupials, including Tasmanian devils and quolls), Peramelemorphia (bandicoots and bilbies), Notoryctemorphia (marsupial moles), and Diprotodontia (koalas, wombats, possums, gliders, macropods, potoroos, and bettongs). Unique features of marsupials include a short gestation period but a long lactation period, with young born in a very immature state and cared for in a pouch in most (but not all) species. This lecture will focus on the marsupial orders most likely to be presented to the North American veterinarian: Diprotodontia (especially sugar gliders, wallabies, and kangaroos) and Didelphimorphia (especially Virginia opossums, with a focus on this species in a wildlife rehabilitation setting). Common disorders in captive sugar gliders (Petaurus breviceps) include dental disease, ocular disease, and gastrointestinal disease, with much of the pathology in this species related to improper husbandry and diet. In captive macropods, common problems include trauma, gastrointestinal disease, pneumonia, toxoplasmosis, and macropod progressive periodontal disease. Virginia opossums (Didelphis virginiana) are the sole native North American marsupial. Common reasons for presentation to wildlife rehabilitators include trauma, predator attacks, and chronic debilitation. In addition to common disorders the veterinarian is likely to encounter in these species, this lecture will also discuss important anatomical and physiological differences from other mammals, clinical techniques, medical treatment, and anesthesia.