The pair visited Whittington Hospital to promote the Wrong Trousers Day
Characters Wallace and Gromit visited a north London hospital as part of a nationwide tour to promote a fund raising event.
The life-sized pair met youngsters at the Whittington Hospital ahead of the Wrong Trousers Day next month.
The event aims to get a million people to pay £1 to wear "rocking wrong trousers" to work or school on 27 June.
Money from the day will fund Wallace & Gromit's Children's Foundation initiatives for sick children.
Over the next month Wallace and Gromit will visit children's hospitals and hospices in Cambridge, Birmingham, Leicester, Nottingham, Sheffield, Manchester, Leeds, Stockton, Newcastle and Glasgow to promote the event.
Simon Cohen, spokesman for the foundation, said: "We had 400,000 people get involved last year, we are hoping that we will get a million this year.
"You just pay £1 which goes to the children's foundation to wear the wrong trousers into work.
He added: "For those people who don't have a pink sequinned suit like myself they might just want to wear jeans into work. It is essentially a bit of fun for a serious cause."
Last year Tony Blair, David Baddiel, Frank Skinner and Sophie Anderton were among the event's celebrity supporters.