The incident occurred on Jockey Lane in Knaresborough at around 11.30pm on Sunday 17 May 2015, and may have happened inside or outside a property on the street. It involved two people, one of whom received a cut to his head requiring stitches.
A 26-year-old man was arrested in connection with the incident. He has been released on bail pending further enquiries.
PC Darian Dundas, of Harrogate Police, said: I am appealing for any witnesses who may have seen or heard anything in the Jockey Lane area to contact the police, as they may have important information that could assist the investigation.
Anyone with information that could assist the investigation is asked to contact Harrogate Police on 101, quoting the reference number 12150081717.
Information can also be passed on anonymously to Crimestoppers by calling 0800 555 111.