Staffordshire Police are hoping the pictures will help the investigation despite being four months old.
A Staffordshire Police spokesman said: "We have released CCTV stills following an assault in Lichfield in August which resulted in a woman sustaining facial and head injuries.
"We were called to Bird Street at 1.30am on Sunday 7 August. A witness reported a woman, in her 30s, being assaulted by an unknown man and woman.
"The victim sustained facial and head injuries and was taken to hospital for treatment. The man was described as having blonde/brown hair and 6ft in height.
"The woman was described as being in her 20s, around 5ft 6ins in height, of a slim build, and having long blonde/brown hair."
Anyone with any information should message the police on on Facebook or Twitter, quoting incident number 074 of 7 August, or call 101.
Alternatively, contact Crimestoppers anonymously on 0800 555 111.