It is understood he was stabbed during the incident on Mayfield Drive, Armadale, at about 22:00 on Wednesday.
A man and woman are currently being questioned by officers.
A Police Scotland spokeswoman said: "Police and emergency services were called and the injured man was taken to Monklands Hospital, where he is currently in a stable condition."
Witnesses are being urged to come forward by the police.
A man is in hospital after being attacked by a large group of men and women in West Lothian.