Police are now appealing for witnesses and information.
A man has also been arrested, police added.
Sussex Police said the incident happened at Brighton Marina.
A police spokesperson said: “Officers responded to a report of a disturbance outside Hollywood Bowl at about 10.30pm on Friday (October 30).
“During the course of an altercation, two men were struck by a vehicle believed to be a black Range Rover.
“The driver of the Range Rover left the scene.
“Two men, aged 22 and 30, sustained serious injuries and were taken to hospital.
“Police are investigating, and a 45-year-old man was later arrested on suspicion of attempted murder, causing grievous bodily harm, and possession of cocaine. He remains in custody at this time.”
Detective Inspector Jennifer Pietersen said: “We are investigating a report that two men were seriously injured when they were struck by a vehicle in Marina Way.
“We are keen to speak with any witnesses and anyone with mobile phone, CCTV or dashcam footage if they have not already come forward.
“We are aware that this incident may cause concern to those visiting the area, however this is believed to be an isolated incident.
“This is a complex and fast-moving investigation, and we urge anyone with relevant information to report it to Sussex Police online or call us on 101 and quote Operation Stargate.”
5. Brighton Marina incident 6.JPG
Police at the scene of the incident. Picture: Eddie Mitchell Photo: Eddie Mitchell