The 65-year-old turned up for the glitzy awards night dressed in a glamorous sparkly blue gown, complemented by an even sparklier pair of diamond earrings.
But when the actress went on stage to accept the Outstanding British Film award for her latest movie "Brooklyn", one of them was missing.
She admitted the earring was "probably worth more" than her home.
"These earrings are borrowed and they are probably the same price as my house. And as I got up on stage I realised one of them was not there," Walters said.
Walters lost out the best supporting actress trophy at the Baftas to Kate Winslet, who won the honour for her role in "Steve Jobs".