Police were called to Glebe Avenue, Ickenham at 6.23pm on Thursday, 14 October following reports of an altercation involving a man with a knife.
Officers attended and identified a victim who had a superficial wound to his chest. He was assessed by paramedics at the scene but declined any further medical assistance.
A search of the area was carried out but the suspect could not be found.
Anyone who witnessed any suspicious behaviour in the area should call 101, giving the reference 6172/14OCT.
Information can also be provided to Crimestoppers, anonymously, on 0800 555 111.