Best Actress nominee Carey Mulligan in Prada and Sarah Jessica Parker in ChanelFor months they've been trying on gowns, talking to designers and booking their beauty treatments.
And this morning it all came together as Hollywood's leading ladies walked the red carpet at the Oscars.
Great British hope Carey Mulligan was joined by her proud mother Nano. The 24-year-old wore what she described as a 'cool' Prada strapless black gown decorated with miniature scissors, spoons and forks, with Fred Leighton earrings
Carey said she would be presenting the Oscar for the short film.
'After that I'm going to party and eat again. I love to eat but for weeks and weeks and weeks I've had to keep the weight down because of the gowns for the awards shows.
'I won't have to walk the red carpet again in high heels, hooray!' she said, laughing.
Carey, a best supporting actress nominee, said she was not at all famous, and loved seeing real stars on the red carpet.
'Meeting Quentin Tarantino was exciting beyond belief,' she said.
Spring nude: Anna Kendrick, Sandra Bullock in a dress designed with vintage material, and Diane Kruger Sandra Bullock wore a shimmering figure-hugging gown in silver.
'It's the dress that looks fantastic, not me', she told the Mail. 'It feels wonderful to wear', she added.
Mariah Carey wore a Valentino dress with a plunging neckline that must have been three sizes too small for her but that didn't stop her wearing it on the red carpet.
Kate Winslet stole the best dress contest in a beautifully elegant strapless gown by YSL with stunning Tiffany yellow diamonds.
Sarah Jessica Parker wore a head-turning strapless gown by Chanel Couture
Sparkling: Miley Cyrus and Cameron Diaz both wore embellished gowns
Three winners: Kate Winslet, Meryl Streep and Helen Mirren all have Oscars at home, while Meryl is nominated for her third this year Monique, star of Precious, wore a gown in the same shade of blue as the dress Gone With The Wind star Hattie McDaniels wore when she won a best supporting actress Oscar in 1939.
Colin Firth wore Tom Ford. 'Well, Tom directed the film,' said Firth of designer Tom Ford who directed A Single Man.
Melanie Griffiths and husband Antonio Bandaras walked the red carpet and Griffiths commented that she was 'glad to be alive' a reference, perhaps, to recent problems with addiction
Flirty in their forties: Demi Moore and Jennifer Lopez in an Armani Prive gown with a revealing bustierJennifer Lopez was every inch the movie star in an Armani Prive gown with a revealing bustier.
The dress, in iridescent icy pale pink silk drew much attention from the red carpet crowd.
Amanda Seyfried, from the Mamma Mia! movie musical, wore a strapless Armani Prive gown in pale green encrusted with Swarovski crystals.
Pastel ladies: Actresses Rachel McAdams and Charlize Theron chose strapless, floor-length gownsNick Park, the British film-maker nominated in the best animated short category for a Wallace and Gromit film called A Matter Of LOAF And Death, stood out on the Oscar red carpet by wearing a luminescent lime green bow tie hand-made from Christmas paper.
Park explained that best animated short is a section that doesn't receive much attention.'It's a way of standing out', Park explained.
British writer Armando Iannucci, nominated with Tony Roche, Jesse Armstrong and Simon Blackwell for adapted screenplay for In the Loop, joked that he and his colleagues took four hours to get into their tuxedos and all got invited to D-list gifting suites.
'Our best gift was socks for puppies', said Iannucci with a straight face.
Classic look: Twilight star Kristin Stewart, actress Giuliana DePandi, and actress Mariska Hargitay show that floor length strapless gowns work at any age
Scarlet women: Actress Jane Seymour, Sigourney Weaver in Lanvin and Jimmy Choos, and Vera Farmiga Penelope Cruz glided along the carpet wearing deep red - a strapless Donna Karan gown with Chopard diamond drop earrings.
The actress, who won best supporting actress Oscar last year, was a contender again last night in the same category for her role as Daniel Day Lewis's sexy mistress in the film Nine.
Sigourney Weaver wore a Grecian-styled gown by Lanvin.
Blue ladies: Precious star Gabourey Sidibe, left, and co-star Mariah Carey in Valentino with Nick Cannon
Battle of the dresses: Avatar star Zoe Saldana and Amanda Seyfried in their princess-style gownsBy the time nominees had spent 40 minutes walking the red carpet they were greeted by waiters holding trays containing flutes of Moet & Chandon champagne which observers noted were gratefully gulped down.
The late arrivals were being rushed down the red carpet.
'We're late and they're desperate to get us inside the hall', said Helen Mirren in a silk chiffon layered gown.
Cameron Diaz, who did not get to bed till five in the morning on Sunday, was the last to arrive at the Kodak Centre. And the wait was worth it as she strode along in a strapless Fifties beaded gown.
Nominees: James Cameron and wife actress Suzy Amis, left, and Peter Sarsgaard and Maggie Gyllenhaal 
Now that's a train: Spanish actress Penelope Cruz in a trailing maroon gownsource: dailymail