Reviewers are warning viewers about an upcoming horror movie that might just be the scariest film of the year.

After its premiere at Sundance, Hereditary received rave reviews by spooked critics - with one calling it "a new generation's The Exorcist".

And now the film's full-length trailer is having the same effect.

The film stars Toni Collette and Gabriel Byrne as a mother and father who are haunted by the ghost of a dead grandmother.


"As they dig deeper into their ancestry, they start to fear about what they might have inherited," The Guardian wrote.

Reviewers have praised the film's ability to deliver clever psychological shocks.

"It didn't play me like a fiddle. It slammed on my insides like a grand piano," wrote AA Dowd for the AV Club.

"It's pure emotional terrorism, gripping you with real horror, the unspeakable kind, and then imbuing the supernatural stuff with those feelings,"

Writing for The Playlist, Jordan Ruimy wrote that it "feels like the culmination of the last 50 years of horror".

USA Today called it a "modern-day horror masterpiece" while The Hollywood Reporter simply said: "Bone-chilling."

Viewers at the film's first screening at Sundance earlier this month took to Twitter to say there would be "no scarier movie this year".

Hereditary is yet to have been given a release date in New Zealand.