Prince William's pregnant wife Catherine left a London hospital on Thursday, three days after she was admitted for treatment for acute morning sickness.
Holding a bouquet of yellow roses and wearing a dark coat, the former Kate Middleton smiled at waiting media as she left the private King Edward VII Hospital with her husband before being driven away.
Asked if she was feeling better, Kate, 30, nodded.
St James's Palace said in a statement: "The Duchess of Cambridge has been discharged from the King Edward VII Hospital and will now head to Kensington Palace for a period of rest.
"Their Royal Highnesses would like to thank the staff at the hospital for the care and treatment The Duchess has received."
William and Kate, who were granted the titles Duke and Duchess of Cambridge after they married in April 2011, have an apartment at Kensington Palace, where William's mother Diana used to live.
Kate was admitted to hospital on Monday afternoon with hyperemesis gravidarum, a severe form of morning sickness that affects about one in 200 pregnant women and is sometimes associated with twins.
The pregnancy is believed to have not yet reached the 12th week.
The hospital apologised on Wednesday after a nurse unwittingly released her private medical details to hoax callers from an Australian radio station.
Sydney's 2Day FM station also said sorry after two presenters posing as Queen Elizabeth II and William's father Prince Charles, got through despite their poor imitations of English accents.
The baby will be third in line to the British throne following last year's historic agreement among Commonwealth realms to end the practise of male primogeniture.