At 12.37am, emergency crews were rushed to Bradford Road in Cleckheaton, at the junction with Balme Road, to reports of six people injured.
The group had been hit by a red Audi and a man in his 40s has suffered life threatening injuries.
Two other men were seriously injured and remain in hospital. Three men were treated in hospital for minor injuries but have since been discharged.
A 49-year-old man has been arrested on suspicion of attempted murder and remains in custody.
West Yorkshire Police believe there was an altercation with the Audi driver and some of the injured men earlier in the evening and they are appealing for witnesses.
A police scene remains in place this morning (Sunday) as officers investigate the incident.
Detective Chief Superintendent Pat Twiggs, of Protective Services Crime, said: “This is clearly a very serious incident and one which has caused understandable concern in the community.
“We have been conducting enquiries throughout the night and have spoken to a number of witnesses.
"I would appeal for anyone who has information and has yet to speak to officers to please get in touch. I would also appeal for anyone who has any dashcam footage of the incident to contact our officers.
“I would also ask for anyone who has CCTV in the local area which may have captured the incident or the red Audi driving in the area to contact officers as soon as possible.
“A scene remains in place while our enquiries continue.”
Anyone with information should contact police on 101, quoting crime reference 13190652982. Information can also be passed anonymously to independent charity Crimestoppers on 0800 111 555.