The Duke and Duchess of Cambridge arrived at The Royal Marsden Hospital in Sutton, greeted by a cheering crowd of fans and hospital staff.
The Royal couple met with patients and their family as part of the opening of the new children's cancer unit.
Designed for the treatment and care of cancer patients, the center in South London costs 18 million pounds, or roughly $28 million U.S. dollars.
This was Kate's second official engagement with husband William, who is President of the Royal Marsden NHS Trust in England.
Kilmeny Duchardt, Reuters.