The European Union's top court ruled Thursday that Austria had no right to hunt wolves, after activists contested killings of the protected species in the Alpine nation.
Several regions of Austria started to allow wolves to be killed last year after reporting that the animals were increasingly attacking livestock.
Environmental groups brought a case to court in Austria's Tyrol province, arguing that hunting wolves violated an EU directive adopted in 1992 protecting the animals.
The Tyrol court asked the European Court of Justice (ECJ) for guidance.
"A derogation from that (wolf hunting) prohibition to prevent economic damage is only to be granted if the wolf population is at a favourable conservation status, which is not the case in Austria," the ECJ said in its ruling.
"The Austrian government has itself admitted that the wolf population in Austria is not at a favourable conservation status."
Twenty wolves have been killed in Austria since last year, according to the country's Bear-Wolf-Lynx Centre.
NGOs estimated there were around 80 individual wolves in the country in 2022, marking a gradual return of an animal that disappeared in the 19th century.
Regional Austrian governments have appealed for the wolves' protection status to be reduced, saying it is no longer threatened.
Following the ruling, the Tyrol government said the regulations it had passed to allow wolves to be shot had "proved their worth" and vowed to continue allowing the animals to be killed.
Tyrol said decisions to kill the animals were made on a "case-by-case basis" and took into account "the special features of our alpine farming".
In its response to the ruling, Austria's branch of the World Wide Fund for Nature (WWF) urged politicians to "move away from their populist false solutions".
Austria's provinces have also failed to "utilise EU funds to promote livestock protection measures or train shepherds" unlike other countries, the NGO said in a press release.