Logging in the Białowieża Forest began in May 2016, but the European Commission took Poland to court past year, arguing that it was destroying a forest that boasts unique plant and animal life.
In its final judgment delivered on Tuesday, the CJEU notes that Warsaw has, however, failed to fulfill its obligations under the Habitats and Birds Directives.
A UNESCO World Heritage site, Bialowieza, which straddles the border with Belarus, is one of Europe's last primaeval forests and home to its largest herd of the almost extinct European bison.
In a blow to Poland's ruling nationalist party, which has also been accused by the European Union of weakening the rule of law, judge Marek Safjan said the logging in the ancient forest endangered many species of birds and insects.
The Polish government has said cutting down trees there was necessary to make forest paths safe for hikers and protect existing trees from a bark beetle infestation. They held protests and brought the case before the court past year.
Poland has faced-off against the EU in several cases, the main one of which concerns the reform of the country's judiciary, which the European Commission says may undermine the rule of law in the country, which has been part of the bloc since 2004.
James Thornton of environmental legal group ClientEarth, one of the groups who complained to the European Commission, said: "This is a huge victory for all defenders of Białowieża forest".
Warsaw in 2016 authorized a almost three-fold increase in logging operations in the Białowieża Forest district and also authorized logging in other areas.
As an interim measure, the ECJ said previous year Poland would be fined 100,000 euros per day if it did not stop large-scale logging in the forest.
- Surgery for Manchester City star Aguero
- Stormy To Release Sketch Of Man Who Threatened Her Over Trump - Lawyer
- An Eye on Beta - EOG Resources, (NYSE: EOG)
- Bayern Munich Lead Chase For Tottenham Hotspur Linked Anthony Martial
- Jessie J wins China's equivalent of The X Factor
- Kathua rape: Jammu Bar Association faces flak
- Bayern Munich midfielder major doubt for Real Madrid clash
- Jameis Winston has fifth-year option picked up by Tampa Bay Bucs
- People's United Financial, Inc. (NASDAQ:PBCT), Lloyds Banking Group plc (NYSE:LYG)
- Teekay Offshore Partners LP (TOO) Given Average Rating of "Hold" by Brokerages