Predator control has traditionally been used to solve the conflict between wild carnivores and humans for resources, leading many carnivore species to the brink of extinction. We are assessing the use of conditioned taste aversion (CTA) as a tool to reduce predation by wild canids. Firstly, we performed an experiment with penned dogs to identify suitable substances to be used as CTA agents in wild canids. We compared pre- and post-conditioning consumption of untreated food as a measure of CTA response. Levamisole (anthelminthic) and Thiram (fungicide) reduced food consumption in the conditioned dogs between 15% and 48% and between 23% and 32% respectively. Both substances generated CTA in dogs with no adverse health effects. A field experiment was performed in two localities with Thiram as CTA agent. Nine foxes were marked with GPS collars and ear tags and simulated partridge nests were monitored with camera-traps. A control area (n = 5 foxes) and a treatment area (n = 4 foxes) were delimited in each locality. During the pre-conditioning phase, nest predation rate was 27.1% and 22.6% in the treatment and control areas, respectively. Foxes were exposed to 60 mg kg-1 of Thiram during the conditioning phase. During the post-conditioning phase, no nest was preyed by treated foxes, whereas foxes in the control area preyed on 13.1% of nests. These results show that Thiram can be safely used as CTA agent to prevent nest predation by foxes. CTA opens new opportunities to mitigate conflicts between humans and predators.