The men, one from Boston and one from Skegness, both died at the scene.
The accident happened at Hale Lane, Frithville, at around 11.40am today.
The men were drivers of the two vehicles which were involved – a red Vauxhall Vectra and a blue Honda Estate.
The man from Boston was in his 30s and the man from Skegness in his 50s.
There were no passengers in either car. Police say next-of-kin of the two men have been informed.
The road was closed in the aftermath of the crash/
Police are appealing for anyone who saw anything or has any information relating to the accident to contact them.
“We would like to appeal to anyone who has information and anyone who witnessed the collision, or saw these cars in the area just prior to 11.40 am today,” a force spokesperson said.
“Please call 101 with incident reference number 168 of 1 October.”