The incident took place on April 13, at around 5:20pm as the man was getting into his car The suspect allegedly punched the victim “repeatedly” and stole his Rolex watch.
Anyone with information should call police on 101 or Tweet @MetCC quoting 5627/13APR.
Information can also be reported anonymously by calling Crimestoppers on 0800 555 111.
Detective Constable Stephen Chubb of the Met’s South Area Command said: “I am very keen to hear from anyone who can identify the male in the picture, but I would also like to speak with anyone who has been offered the watch for sale.
“Being the victim of a violent robbery has a lasting effect that goes far beyond a loss of property – if you can help us find the person responsible please do the right thing and get in touch.”
The statement from Metropolitan Police said: “Detectives are appealing for the public’s help to identify a man following a high value watch robbery in Croydon.
“The offence occurred on Thursday, 13 April at around 17:20hrs in Grosvenor Road, SE25.
“The victim, aged in his 70s, was approached by a male as he got into his car.
“The suspect punched the victim repeatedly and stole his Rolex watch.”