The new Harry Potter movie is the first in the blockbuster series to be given a 12A certificate rather than a PG, the CBBC Newsround website has learned.
Goblet of Fire has its world premiere in London on 6 November
Children under 12 will only be able to watch Harry Potter and the Goblet of Fire if accompanied by an adult.
"Younger viewers could be frightened by some of the more intense scenes," said the British Board of Film Classification (BBFC).
The film contains "moderate fantasy violence, threat and horror", it added.
"At 12A we allow moderate level violence, but without focus on injuries or blood," the BBFC's spokeswoman continued.
The movie was passed with no cuts.
At 157 minutes Goblet of Fire is the second longest Potter film, three minutes shorter than Harry Potter and the Chamber of Secrets.
The film, released in the UK on 18 November, has been given a PG-13 rating in the US.
The US rating signifies the film may be inappropriate for pre-teens but it does not restrict children under 13 from admittance.