A very successful, wealthy lawyer, Edward Lewis, hires a beautiful and unlikely prostitute, Vivian Ward (Julia Roberts), from Sunset Blvd to bring along to various business events. An attraction developes between the two, and Edward finds it harder and harder to let the infectious, kind-hearted Vivian go.
Businessman Edward Lewis (Richard Gere) breaks up with his girlfriend, who doesn't want to be at his "beck and call" at a swanky party held by his partner Philip Stuckey, and cuts loose in Stuckey's Lotus. He gets lost and stops along Hollywood Boulevard for directions from hooker Vivenne (Julia Roberts). She charges, gets in and ends up driving him to his hotel in Beverley Hills. He asks her up to his penthouse suite on a whim and pays her to stay all night, although seems uncomfortable at first.
The following morning he asks her to stay all week for $3000. He also gives her money for clothes and says she needs to be at his "beck and call" with no strings attached. She calls her room-mate Kit (Laura San Giacomo) to leave her money for the rent, and goes shopping on Rodeo Drive for more appropriate clothes. However, snooty saleswomen won't serve her as she is still dressed like a hooker, and she returns to the hotel, where she gets stopped by the Hotel Manager, Barney (Hector Elizondo). He wants to make it clear that they are making an exception having her at the hotel as Edward is such a special guest. Vivienne gets upset as she still has no outfit for dinner, and Barney helps her, along with coaching her on dinner etiquette. When Edwards returns, he is amazed by Vivienne's new look. The business dinner goes well, but Edward is preoccupied with the deal afterwards.
The next day, Vivienne tells him about the experience shoppingt the previous day, and Edward takes her back to spend an obscene amount of money on clothes, leaving her to go back to his work as she is transformed from hooker to lady. She goes back the shop from the previous day to show them the big mistake they made! Back at hotel, she looks like a genuine guest, but when Edward gets home he is still busy with work, and they take a bath together and talk into the night about their pasts and how they ended up where they are today.
The following day, Edward takes Vivienne to the polo. While Vivienne chats to David Morse, the grandson of the man involved in Edward's latest deal, Philip is worried she is a spy. Edward reassures him by telling him how they met, and Philip then comes on to Vivienne. When they return to the hotel, she is furious with Edward for telling him, and plans to leave, but he persuades her to see out the week. Edward leaves work early the next day and takes Vivienne on a date to the Opera in his private jet. She clearly is moved by the music, and says "If I forget to tell you later, I had a wonderful time tonight". On returning to the hotel, he falls asleep (the first time we have seen this) while she is getting ready for bed, and she kisses him on the lips - she doesn't do this with clients - and they make love as partners, rather than client and hooker. Over breakfast, Edward offers to put her up in an apartment so he can continue seeing her, but she feels insulted and says this is not the fairytale she wants. He then goes off to work without resolving the situation. Kit comes to the hotel and sees that she has fallen for him, but she denies it.
Edward meets Morse, about to close the deal, and changes his mind at the last minute. His time with Vivienne has shown him another way of being - taking time off and enjoying life - and working. He wants to create things rather than just making money. Philip is livid, and goes to the hotel. Vivienne is there and he blames her for changing Edward - he comes onto her again, and then hits her before Edward returns and pulls him off and chucks him out.
Vivienne leaves, and is seen back at home with Kit, packing up to leave for San Franscisco. Edward gets into the car with the chauffeur that took her home, and rather than going to the airport, he goes to her apartment and climbs up the fire escpae (despite being afraid of heights) with a rose in his mouth, to woo her like in a fairy-story.