The Western Australian Environmental Protection Authority (EPA) has issued written guidance on its expectations for terrestrial vertebrate fauna surveys to support environmental impact assessments (EIA). We report on one of the few circumstances where a direct comparison of the results from an EIA vertebrate fauna survey, that did not, in our opinion, appear to conform with the EPA's guidance statement expectations but was seemingly accepted by the EPA, and a comprehensive terrestrial vertebrate fauna salvage program were undertaken at the same site. This has enabled us to comment on the consequences of not undertaking a survey that complies with the EPA's expectations. Excluding incursions by non-local species, bats and avian fauna, ∼33% of terrestrial vertebrate fauna species recorded during the fauna salvage program were not reported as being present in the EIA survey. The relative abundance of various species differed appreciably between the fauna salvage program and the EIA survey, and an endangered species present in the project area was not identified as likely to occur. We believe these differences occurred because of a single-season EIA survey, insufficient trapping effort, a failure to survey an important fauna habitat, the presumption that a threatened species would be absent due to a lack of local records and records in the available habitat types. A comprehensive review and rewrite of the outdated Western Australian EPA vertebrate fauna survey guidelines and a requirement for proponents and environmental practitioners to meet (or exceed) the revised guidelines are the recommended outcomes.