<p>If eradication has become infeasible, containment of an invasive species may be a practical alternative. Like all management actions, however, containment comes with costs, so it is important to quantify the potential benefits accruing from a proposed containment action. Here we examine the ongoing spread of the toxic, invasive cane toad (<i>Rhinella marina</i>) across northern Australia, and a proposal to contain their spread and prevent their arrival in Australia’s Pilbara bioregion (178,000 km²), ca. 500 kms south of the toad’s 2024 invasion front. We then evaluate the likely biodiversity costs if toads spread to the Pilbara. Under a ‘do-nothing’ scenario, toads are predicted to arrive via natural dispersal in the Pilbara between 2035 and 2055. They are predicted to colonise almost the entirety of the Pilbara bioregion. We predict that 25 vertebrate taxa resident in the Pilbara are likely to show population declines driven by lethal poisoning. Of the 25 at-risk taxa, eight are endemic to the Pilbara. A further two taxa are not endemic to the region but toad colonisation of the Pilbara will result in &gt; 90% of their range being occupied by toads. Hence, we predict that the spread of toads to the Pilbara will cause an additional five mammals and four reptile species to be added to the threatened species list, and cause another species to be upgraded in threat status. These likely losses will also have cultural impacts for the First Nations people of the Pilbara, and cause economic impacts for the Pilbara’s primary industry; mining. Overall, our results show that predicted losses of the no-action option are high, and likely justify an attempt to exclude toads through establishment of a containment zone.</p>