A man suffered a fractured eye socket in an early hours attack in Otley.
The 29-year-old victim, who is from the town, was found injured in Boroughgate at about 3.20am on Sunday.
He was taken to Leeds General Infirmary by ambulance for treatment to the fracture and cuts to his face before being released.
Detectives are now trying to piece together what happened and want to hear from anyone who witnessed the man being assaulted or who has any information.
Call Det Con Andrew Queen at Pudsey police station via the non-emergency number 101 or call Crimestoppers anonymously on 0800 555 111.