At around 1am on Friday 22 July, a 19-year-old local man was approached by another man while he was on the dance floor of the Viper Rooms, a nightclub at the Royal Baths on Parliament Street.
The offender struck the 19-year-old victim over the head with a bottle, causing a cut above his right eye and bruising to his forehead.
The victim was treated at Harrogate District Hospital and discharged later the same morning.
Officers are appealing to clubbers in the Viper Rooms on Thursday evening or Friday morning to come forward if they either witnessed the assault or have any information relating to the incident.
DC Stephen Williams of Harrogate CID, said: “This was a nasty assault which appears to be unprovoked. I am appealing to anyone who was in the Viper Rooms and saw what happened to contact the police.”
Anyone with any information is asked to contact Harrogate CID on 0845 60 60 247, quoting reference 12110121546. Or, you can give information anonymously to Crimestoppers on 0800 555 111.