We used digital map overlays in a geographical information system (GIS) to quantify the potential impact of dryland salinity on the threatened flora and fauna of New South Wales (NSW). Geographical areas of conservation priority were identified based on richness of threatened species with distribution records overlapping dryland salinity. Two alternative schemes – Interim Biogeographical Regionalization for Australia (regions) and catchment boundaries (catchments) – were used to subdivide NSW. Sydney Basin, North Coast and South-western Slopes regions – and Hunter, Sydney, Macquarie, Murrumbidgee and Lachlan catchments – were identified as priority areas with more than 10 salinity-overlap species present. Five threatened plant species were identified as priority species due to more than half of their known distributions overlapping areas of dryland salinity. Threatened animal species of most concern had 10–50% of their records overlapping areas of dryland salinity. Our findings demonstrate that landscape exposure to dryland salinity should be used in conjunction with total richness of threatened species for prioritizing conservation of geographical areas with respect to the potential impact of dryland salinity on threatened species.