Two people suffered serious injuries in the accident south of Auchtermuchty just after 8.30pm on Saturday night.
One man was taken to Ninewells Hospital were he is in a critical condition.
A woman also involved in the accident, on the B936 Auchtermuchty to Dunshalt road, was taken to the Victoria Hospital in Kirkcaldy where he condition is said to be stable.
The incident involved a southbound Fiat Stilo and northbound Peugeot 206.
The road was closed in the wake of the accident for investigations to be carried out.
It was reopened at 3.50 this morning.
Police are appealing for anyone who witnesses the incident or saw either of the cars shortly before the collision to get in touch.
Sergeant Derek Allan said: “This was a very serious collision that has left two people badly injured.”
With inquiries continuing he asked witnesses to call the police on 101.
