The 29-year-old man was found outside the Town Hall pub in Richmond in the early hours of Friday, October 5.
Paramedics called to the scene in Market Place contact police at around 12.30am to report a serious assault.
The man, who had suffered head injuries, was taken to Darlington Hospital for further treatment.
He later underwent surgery for a fractured cheekbone.
North Yorkshire Police today issued an appeal for information about the incident and a second man they want to trace.
A spokesman said: "Police are keen to identify a man who was seen in the area at the time of the assault, who may hold information that is important to the investigation.
"He is described as 5ft 9in, with dark hair and was wearing a black t-shirt with a shiny logo the front."
Anyone who recognises the description of the man, or who witnessed the incident, is asked to contact police.
Phone the force via 101, select option 1 and pass any information to the Force Control Room, quoting reference 12180186005.
Information can also be passed on anonymously via the independent charity Crimestoppers on 0800 555 111.