The Jehovah's Witnesses group has been banned in Russia after being described as "a threat to the public".
The country's highest court declared it to be an "extremist organisation" in a ruling that means the country's 175,000 adherents will not be able to congregate or distribute literature.
In March, Russia's Justice Ministry had asked the Supreme Court to ban the organisation which got a warning to halt "all extremist activity".
A spokesman for the group, Yaroslav Sivulsky, said it will appeal the decision at the European Court of Human Rights.
"I didn't expect that this could be possible in modern Russia, where the constitution guarantees freedom," he said, according to the AFP.
Russia has taken the hardest stand of any country against the faith, whose followers go from door to door and refuse military service and blood transfusions. The faith was founded in the US in the 19th century.
Under the rule of Joseph Stalin it was outlawed, but its ban was lifted in 1991 after the fall of the USSR. It has been criticised in recent years and accused of recruiting children.
A human rights group, Sova, said that the movement has been on the receiving end of an "official repressive campaign". The Russian authorities say that the faith destroys families, fosters hatred and threatens lives.
Justice minister Svetlana Borisova said: "They represent a threat to the rights of people, public order and public safety."