Priestely, who played heartthrob Brandon Walsh for eight years on the long-running 90's TV series Beverly Hills, 90210, was flown to the University of Kentucky Hospital in Lexington after the crash.
Henry Bock, the medical services director for the Indy Racing League, told Reuters that Priestley was "stable and responding" and was listed in serious condition. He is currently undergoing testing.
The accident occurred Sunday morning at the racetrack in Sparta, Ky., as the 32-year-old actor prepared for the race. Priestley, who drives for Kelly Racing, had been working toward the Indy Racing Infiniti Pro Series season since July.
Priestly's vehicle crashed coming out of the second turn in the final practice run. He was injured when his car crashed head-on into the wall.
Priestley won a 1998 Grand-Am race at the Mid-Ohio Sports Car course, and he has also worked as an announcer for the Indy Racing League broadcasts for ABC Sports, including the Indianapolis 500.
The Canadian-born actor left 90210 in 1998 to persue big-screen features, including his latest film--the romantic comedy Cherish.
Just last year, the actor spent five days in a private L.A. work-release program after pleading no contest to a felony drunken-driving charge. He was arrested in December 1999 after he crashed his Porsche into a power pole, trash cans and a parked car in the Hollywood Hills.
Priestley also escaped injury last April when his speedboat collided with another during the Fountain Miami Super Boat Grand Prix in Miami.