The younger son of Prince Charles and Diana, princess of Wales, changed a baby doll's diaper at the opening of the Nottingham headquarters of the Headway charity, which provides support to people with brain injuries through a network of groups across Britain.
The charity, for which his late mother served as a royal patron, uses tasks like diaper-changing to rehabilitate people with brain injuries.
Harry, 28, also tried on goggles to simulate a brain injury's effects, ABC News said, and met with a former Royal marine who suffered a brain injury while serving in Afghanistan, the BBC said.
He was greeted by hundreds of schoolchildren.
At a different stop, Harry later pretended to be a news co-anchor with a female broadcasting student.
He did the brief co-anchor work, where he read a "top story" and pretended to lead in to a weather report, at Nottingham's Confetti Institute of Creative Technologies, which teaches TV and film production.
The institute is part of a consortium preparing to launch Notts TV, the first local TV station in Nottingham, famous for its ties to English folklore's legend of Robin Hood.
The Nottingham visit, the prince's first, was among a number of charity public appearances Harry has made returning from Afghanistan in January after a four-month tour of duty.
He is a captain in the British army and a helicopter pilot.
Harry is to visit the United States May 9-15 to support veterans, including wounded U.S. veterans at Washington's Walter Reed Army Medical Center.