Leeds District CID would like to speak to anyone who witnessed or has information about an assault on Harehills Road at about 9.20pm on Sunday, May 1.
Police were called to the area following a report of a fight taking place there.
Officers attended and located a 41-year-old man who had been assaulted, potentially with a weapon, and suffered a superficial arm injury.
He was treated in hospital and later discharged.
Anyone who saw what happened or has information is asked to contact Leeds CID on 101 referencing police crime number 13220233928.
Information can also given online at www.westyorkshire.police.uk.101livechat or anonymously to the independent Crimestoppers charity on 0800 555 111.