The queen’s husband, 99, previously underwent a heart procedure at St Bartholomew’s Hospital.
After a successful cardiac operation, Prince Philip has returned to King Edward VII Hospital.
Philip had undergone a heart procedure for a pre-existing condition at St Bartholomew’s Hospital on Wednesday after being transferred to a heart unit in London.
The Palace said in a statement: “Following the successful procedure of the Duke of Edinburgh at St. Bartholomew’s Hospital on Wednesday, His Royal Highness was transferred to King Edward VII Hospital this morning. The Duke is expected to remain in the hospital to continue treatment for several days.”
Philip has now spent more than two weeks in the hospital, his longest stay, leading to fears for his health due to his advanced age.
He will turn 100 next June 10.
The prince was first admitted to King Edward VII Private Hospital in central London on 16 February.
Buckingham Palace initially said it was expected to stay there “a few days” after entering unans helplessly.
Later, the palace said he was being treated for an infection.