The 74-year-old star phoned the Marylebone, London, branch of Barnardo's to offer them the chance to pick up her some of her old items from Ralph Lauren, Paul Mayer and Sonia Rykiel.
The store's manager, Russell Lewendon, said: 'We are over the moon with this generous donation. There has already been a lot of interest in the items so people need to get down here fast if they want to snap up a celebrity bargain.
'It's great that Dame Shirley thought of us, as although we welcome all donations, it's a special treat to be able to see the clothes of such a star.'