"No change has been made to the nature of this cult, they are the same people with the same ideology and manifestation," said Iran's foreign ministry spokesman, Hassan Qashqavi.
The spokesman described the Luxemburg court decision as hasty and politically motivate, saying the group's criminal and savage acts are known to everyone.
Qashqavi commended Canada for keeping the Mojahedin Khalq Organization (MKO) group on its list of terrorist organizations.
The MKO is blacklisted by many countries, including EU member states, as a terrorist organization responsible for violent operations in Iran following the 1979Islamic Revolution and during the 1980-88 Iraqi imposed war on Iran.
The group is known to have supported Iraq's former dictator, Saddam Hussein, and is accused of collaborating with the Baath regime in the massacre of Iraqi Kurds.
The Luxembourg-based Court of First Instance ruled on December 4, that the EU was wrong to freeze the funds of the MKO. The court urged the European Union to remove the group from its terror list or appeal the court's decision.