The National Society for Prevention of Cruelty to Children (NSPCC) will be holding an auction at Bonhams in London and the picture of Kate is sure to make it a roaring success.
The portrait shows a topless Kate wearing nothing but a gold pair of hipsters and a pout.
Other images being sold are a topless picture of Christy Turlington, taken by Patrick Demarchelier in 1986 and a photo of Florence Welch by Isreali photograper Nadav Kander.
Barry Lategan's famous shot of a doe-eyed Twiggy taken in 1966 will also be sold at the auction.
Andrew Flanagan, chief executive of the NSPCC added: 'We are very pleased to be involved in such an exciting auction. Without support such as this, we would not be able to deliver vital therapeutic services.'