Kurt Busch confirms NASCAR retirement: "Too many obstacles for me to overcome"
Busch suffered a concussion in qualifying at Pocono last year.
He had already confirmed that he wouldn’t return to full-time racing this year.
It was hoped Busch might feature in select races but he has now closed the door on an epic career.
"Sometimes father time can catch up to your dreams," he said.
"My incredible team of doctors and I have come to the conclusion that at this point in my recovery there are just too many obstacles for me to overcome and get back to 100%.
"So after 23 years behind the wheel and 45 years of living and breathing this dream, I am officially announcing my retirement from NASCAR Cup Series competition."
Busch is now 45, and is a 34-time NASCAR race winner.
He ends his career with 776 Cup stars, the first of which was in 2000.
Busch is 25th on the list for all-time wins.