A man was assaulted in Castle Street and police are asking witnesses to come forward.
The victim, a man in his 20s, was assaulted on December 29.
He did not require hospital treatment.
Wiltshire Police attended the scene in Castle Street at around 11.30pm at which time the offender had left the scene.
The offender was described as being a white man, about 50-60 years old, with a grey beard and wearing dark clothing.
He was of slim build and was about 5 feet 10 inches tall.
A spokesperson for Wiltshire Police said: "We attended Castle Street Salisbury at about 11.30pm on 29th December in response to a reported unprovoked assault on a man in his 20s."
Anyone with information or potential witnesses should contact Wiltshire Police on 101 quoting log 54220135837.
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