Police are appealing for witnesses following the incident in Musselburgh, which took place between 3.30pm and 5.30pm on Monday.
A man arrived at the pensioner’s home on the town’s Pinkie Road claiming to be carrying out work on behalf of the council.
But while he kept the woman occupied an accomplice sneaked in to steal the cash from her bedroom.
The first suspect is described as around five foot tall with short, dark, curly hair. He was wearing dark clothing and spoke with a local accent.
He also brandished an identity card that said PH Jones on it.
The woman was unable to give a description of the second man.
A police spokesman said: “The bogus caller made off with a substantial sum of cash, and we are appealing for any information that can help us track down those responsible.
“Anyone who was in the area of Pinkie Road yesterday afternoon who noticed anyone acting suspiciously there should contact police immediately.
“Similarly, anyone who recognises the description of the suspect should get in touch.”
Anyone with information should contact police on 0131 311 3131 or Crimestoppers anonymously on 0800 555 111.