Detectives in Bradford today released details of the "despicable crime" as they appealed for witnesses to come forward.
The victim had been walking his dog along Etna Street at around 11am yesterday when he was approached by a man wearing a woolly hat.
The man engaged him in conversation and walked with him towards Hew Clews, before following the victim into his house.
He struggled with the victim and stole cash before leaving out the front door.
Detective Inspector Ryan Bragg, of Bradford District CID, said: “This was a despicable crime against an elderly man and we are keen to speak to anyone who may have seen a male matching the above description in the Hew Clews area at around 11.15am yesterday.
“Our enquiries are continuing today and anyone who may be able to assist is asked to contact us."
The robber is described as a white man who is believed to be in his twenties.
He was clean shaven and was also wearing a jacket and jeans.
Call Bradford District CID on 101, quoting crime reference 13180047831.
Information can also be reported anonymously to the independent charity Crimestoppers on 0800 555 111.