The woman from Skidby had been a rear seat passenger in the car which collided with a tractor and trailer on Sunday, October 23.
Humberside Police today said she passed away at Hull Royal Infirmary this weekend.
A spokesman said: “The 88-year-old woman was a rear seat passenger in a red Hyundai i20 car, which was involved in a collision with a red Massey Ferguson tractor and trailer at 9.40am on October 23 on the westbound carriageway of the A63 between South Cave and North Cave.
“She sustained life threatening injuries and was taken to Hull Royal Infirmary where she passed away on Saturday October 29.”
The driver of the Hyundai was uninjured, but the front seat passenger and the driver of the tractor sustained minor injuries.
Officers are still seeking witnesses and information about the collision.
Anyone with information is asked to call 101, referring to log number 188 of October 23 2016.