The victim, who is in her 50s, was in Asia takeaway in Fitzwilliam Street on 30 October when 39-year-old Andrew Harding slipped his hand into her coat pocket and stole her mobile phone.
The woman only noticed her phone, along with her bank card and £20 cash that were stored in the phone’s case, had gone when she went to pay for her order.
CCTV footage was checked which showed Harding stand close to the woman, remove the phone and place it in his own pocket.
Harding, of Myrtle Avenue in Welland, was arrested on Monday (29 November) and charged with theft from a person.
He appeared at Cambridge Magistrates’ Court on Tuesday (30 November) where he admitted the offence and was sentenced to ten weeks in prison.
PC Tom Todd, who investigated, said: “I would urge people to be alert to this type of theft particularly as we see our city centre get busier in the run-up to Christmas.
“A determined thief can often go unnoticed and easily remove valuable items such as mobile phones, purses and wallets from pockets and handbags if they are open.
“If anyone sees suspicious activity, please either call police immediately or alert a member of shop staff or security.”
Advice on how to best protect against pick-pockets can be found on Cambridgeshire Police’s website.