Police have released CCTV images of four people they want to trace in connection with the theft, which happened at Oxfam in Darley Street, Bradford.
A West Yorkshire Police spokesman, said: "An 82-year-old female was in the shop browsing when she hung her handbag on her walking frame.
"The suspect/suspects unzipped her bag and stole her purse. They made off from the scene."
The theft happened at around 11am on Friday February 23, but police only released details today. (Sat March 10)
Anyone who recognises any of the people captured on CCTV is asked to contact PCSO Mohammed Rauf at Bradford Police via 101 quoting crime reference 13180090916.
Information can be passed to Crimestoppers anonymously on 0800 555 111.