Emergency services were called to the scene of the collision near Ulceby Cross at around 4.15pm yesterday.
The incident involved a yellow Nissan Note, a black Suzuki Jimny and a grey Hyundai i10
A Lincolnshire Police spokesman said: “The driver of the Suzuki, a man, was taken by air ambulance to Hull Royal Infirmary with serious injuries.
“The driver of the Nissan Note, a man, was taken to Boston Pilgrim Hospital with injuries not thought to be serious.
“The road was closed for several hours while emergency services attended. It re-opened at around 11pm.”
• If you witnessed the collision or have any information, call police on 101 and quote incident number 313 of June 5.