The Shaukat Khanum Memorial Cancer Hospital and Research Centre was started in the early 1990s by the cricket-hero-turned-politician Imran Khan, who is now Pakistan's prime minister, and whose first wife Jemima Goldsmith was a friend of the late princess.
William and Kate's visit brought back memories for many Pakistanis who still love the late Lady Diana for her humanitarian work. Diana visited the facility in the 1990s and met with cancer patients and attended a fund-raising event. The hospital says it has been providing free treatment to 75% of its patients for the last 24 years.
Also on Thursday, the royal couple played cricket with children and members of Pakistan's cricket team at the National Cricket Academy.
Their day began with a birthday party for three orphaned children at a charitable organization, SOS Children's Village. They chatted with the children and Kate spoke in Urdu to congratulate them.
William and Kate later visited the historic Badshahi mosque, also previously visited by William's mother during one of her visits to Lahore.
According to Britain's Press Association, William and Kate walked on a red carpet through the holy building with the prayer leader before being given a tour of the inside, where they heard a verse from Islam's holy book.
Since arriving, the royal couple have been advocating for girls' education and visited a girl's school in Islamabad. They addressed climate change while in Pakistan's northern region, where glaciers are melting at an alarming rate.
Pakistani authorities have deployed hundreds of police and paramilitary security forces for the protection of the visiting royal couple, who will return home Friday.
After their arrival in Pakistan, they met with Pakistan's President Arif Alvi and Khan, who had lunch with them at his sprawling office.
Prince William has thanked Pakistan for the warm welcome and hospitality he said has been extended to him and his entourage.