10 of the 12 nominated acts walked the red carpet to discuss their albums ahead of the ceremony in London's Mayfair.
Watch Digital Spy chat to the nominees below:
Adele, who was one of the favourites to scoop the prize with her record-breaking album 21, was the only act not to perform on the night due to illness. She told the audience: "Thank you so much for having me, I'm gutted I can't perform," before host Jools Holland urged the crowd to wish her back to health.
The Barclaycard Mercury Prize is in its 20th year, and is voted for by a panel of music industry executives and experts that this year included singer-songwriter Corinne Bailey Rae.
Previous winners include Elbow, Primal Scream, Arctic Monkeys, Pulp, Speech Debelle, Antony and the Johnsons and last year's winners The xx.
PJ Harvey's Mercury win marked her second after Stories from the City, Stories from the Sea in 2001. Watch her interview with BBC Radio 2's Huey Morgan:
PJ Harvey will play a one-off show at the Royal Albert Hall on October 30.