A 66-year-old man suffered head injuries when he was assaulted outside Milton Keynes railway station on Friday evening.
The incident happened at around 7.15pm on January 23, when the victim was waiting outside the station and became involved in an an altercation with the male passenger of a grey coloured taxi.
The pensioner was pushed to the ground during the argument, and suffered a cut and swelling to the back of his head.
The offender was black, 6ft, stocky, and his mid-thirties. He was wearing a dark coloured duffel coat.
If you have any information that could assist the police with the investigation, contact PC Joseph Wiffen on the 24-hour non-emergency phone number, 101.
Alternatively call Crimestoppers, anonymously, on 0800 555 111 or online at www.crimestoppers-uk.org