A 69-year-old man was robbed in Lincoln on Friday evening.
The incident happened at around 5.30pm on June 27, when the victim was attacked and robbed of his wallet near the garages leading to Hermit Street, off Portland Street.
Police said the robber approached the man from behind and pushed him to the ground before stealing his wallet and running off along Hermit Street.
He is described as being aged around 30, about 5ft 6in in height, of thin build and wearing a dark jacket and light coloured tracksuit bottoms.
Anyone who witnessed the incident is asked to contact Lincolnshire Police on 101 quoting incident 328 of June 27.
Alternatively contact the independent charity Crimestoppers anonymously on 0800 555 111.