A man suffered fractured ribs and a punctured lung after he was attacked in the street.
The man, aged 32, was walking with his girlfriend in Sackville Street, Ravensthorpe, at 2am on Saturday when he was attacked by a passenger who got out of a car.
Police said the car involved was thought to be a black Ford Mondeo on either an 02 or 52 plate.
Det Insp Ian Thornes, of Kirklees CID, said investigations were at an early stage and there was no clear motive.
The victim suffered serious injuries and was detained in hospital.
The attack happened near the junction with Red Laithes Lane and police have appealed for anyone with information to contact them via 101 or through Crimestoppers, anonymously, on 0800 555 111.
In unrelated investigations, police would like to speak to the people pictured in the image gallery below. The people pictured in the images may be witnesses as well as suspects. If you recognise anyone, contact police on 101 quoting the reference number on the image caption.