A man suffered head injuries after being assaulted in Cleckheaton.
The attack happened on Westgate at around 12.20am on Sunday.
Police found the victim lying unconscious on the pavement.
He was taken to Dewsbury and District Hospital for treatment.
Two men, aged 47 and 20, have been arrested on suspicion of assault.
Anyone with any information should contact police on 101 or Crimestoppers on 0800 555111.