Where habitat loss is rapid, formerly common species may be at risk of extinction. We provide a method for using habitat mapping data and herbarium records to identify plant species that are threatened by the rapid conversion of brigalow forest, a widespread habitat type in eastern Australia that has been decimated over the last 60 years. The method weights species depending on the strength of their association with the brigalow forest habitat and their association with the Brigalow Belt region where the clearance of native vegetation has been extensive. The process identifies 56 out of a total of 1229 plant species that are at greatest potential risk. Twenty of the 56 species also occur in habitats that have not been extensively cleared. Of the remaining 36 species, 11 are closely associated with brigalow forest, which in general has been more extensively cleared than other habitats. The method revealed several species potentially imperilled by habitat loss that have not previously been identified by formal listing of threatened species. The rate of habitat loss for the target species can be clearly documented, although further survey is required to determine the potential persistence of species in habitat that has been modified by clearing and an estimate of generation length of the plant species is required in order to assess this decline against IUCN threat categories. The method has broad application in situations where there are records of species and documentation of habitat loss.