A 69-year-old Spilsby woman has been airlifted to hospital after a crash on the A157 at Withern, near Alford.
The crash happened at around 1.45pm and involved a lorry and a Citroen.
The woman, from Spilsby, was taken to Hull Royal Infirmary with internal injuries.
The lorry driver, a man from Scotland, has been treated for less serious injuries.