The results of a trapping and spotlighting survey in Victoria of the squirrel glider, Petaurus norfolcensis, coupled with examination of historical records showed that the species is restricted to the Riverine Plains, Northern Uplands and northern slopes of the Western Highlands. Within these regions squirrel gliders inhabit remnant woodlands or open-forests which have mature or mixed-age stands of more than one eucalypt species, or riparian open-forests of Eucalyptus camaldulensis. The mixed-species stands which support squirrel gliders invariably include gum-barked and high nectar-producing species including some which flower in winter. The riparian open forests typically contain mature Acacia dealbata which may provide an important winter carbohydrate source. The squirrel glider was often the only arboreal mammal detected at a site; if another species was present it was usually the common brushtail possum, Trichosurus vulpecula. Other petaurids rarely occurred at the same site. We suggest that in Victoria the ecological tolerance of the squirrel glider is narrow 'and that the species should be considered vulnerable because most of its habitat has been cleared for farming. Commercial exploitation of timber and grazing of stock in much of the remaining habitat places further stress upon the small, fragmented populations of this species.