Context. The Felixer grooming device ('Felixer') is a lethal method of feral cat control designed to be cost-effective and target specific. Aims. This study aims to test the target specificity of the Felixer in Tasmania, with a particular focus on Tasmanian devil and quoll species due to the overlap in size, habitats and behaviour between these native carnivores and feral cats. Methods. Our study deployed Felixer devices set in a non-lethal mode in nine field sites in Tasmania, one field site in New South Wales and two Tasmanian wildlife sanctuaries. Key results. Our study recorded 4376 passes by identifiable vertebrate species including 528 Tasmanian devil passes, 507 spottedtailed quoll passes and 154 eastern quoll passes. Our data showed that the Felixer can successfully differentiate quoll species from feral cats with spotted-tailed quolls and eastern quolls targeted in 0.19% and 0% of passes, respectively. However, Tasmanian devils and common wombats were targeted in 23.10% and 12% of passes, respectively, although sample size was low for common wombats (n = 25). Conclusions. The Felixer could not reliably identify Tasmanian devils and possibly common wombats as non-target species. Further data is needed to confirm the potential for impacts on the common wombat and other potential nontarget species in Tasmania, and the likelihood of the toxin being ingested by falsely targeted individuals. Implications. Our study suggest that the Felixer device is safe for use in the presence of two species of conservation concern, the eastern and spotted-tailed quoll. It also supports evidence from previous studies that the Felixer is unlikely to impact bettongs and potoroos. Use of Felixer devices across much of Tasmania would have to balance the conservation or economic benefits of cat control against potential impacts on Tasmanian devils. We suggest that active Felixer deployments be preceded by surveys to establish the range of species present at the control site, and the season of control considered carefully to minimise potential impacts on more susceptible juvenile animals. In addition, modifications to the Felixer device such as the proposed incorporation of AI technology should be tested against the Tasmanian devil and other non-target species.