Rothschild's rock-wallaby (Petrogale rothschildi) is endemic to the Pilbara and Ashburton regions of Western Australia. This large species of rock-wallaby is currently not recognised as threatened but is poorly known. Feral cats are a serious threat to many mainland Australian mammals, including some species of rock-wallaby, however their impact on P. rothschildi is largely unknown. Here we provide the first account of feral cat predation on Rothschild's rock-wallaby, which was confirmed via genetic analysis. Common rock rats were abundant at the time and are the primary prey for cats, suggesting this was an incidental predation event by this highly opportunistic predator.