Exotic marsupials are becoming popular companion pets, yet little pharmacologic information is available to the practitioner. Species include sugar gliders (Petarus breviceps), South American (Brazilian) short-tailed opossums (Monodelphis domestica), brushtail possum or "phalanger" (Trichosurus vulpecula), and wallabies: Bennett's (Macropus rufogriseus rufogriseus) and Tammar or Dama (Macropus eugenii). Guidelines for logical choices of medications based on allometric scaling, gastrointestinal tract anatomy and physiology, and liver metabolism are given. An example of scaling and a formulary based on anecdotal, published medications are provided.