Blue Peter viewers are being given the chance to get their design on a 50p coin for the London 2012 Olympic and Paralympic Games.
The contest is only open to kids aged between six and 12.
The winner will be the first child ever in the UK to have their work featured on a coin which will be used by people across the country to buy things.
The entries will be seen by a panel of judges, and the coin with the winning design will be issued in 2010.
The Blue Peter contest is one part of a wider competition being run by the Royal Mint, which will see 29 Olympic designs appear on coins.
Blue Peter editor Tim Levell said: "This is the first time the Royal Mint has given a child the guaranteed chance to design a circulation coin, so this really is making history."
The winner will also be given a gold version of their design, and get the chance to see it being turned into coins at the Royal Mint in south Wales.
Full details of the competition will be revealed on Blue Peter on BBC One at 4.35 pm on Tuesday 13 January.