Police are appealing for witnesses to the crash on the A643 between the Armley Gyratory and the M621 on Saturday morning.
The incident happened at around 10.40am. A silver Toyota Yaris, which was travelling towards Leeds, has crossed the central reservation and collided with an oncoming Peugeot 807.
The driver of the Toyota had to be cut free by the fire service and was taken to Leeds General Infirmary where he was kept in overnight for observation.
The driver and passenger of the Peugeot were out of their vehicle upon police arrival and treated at Leeds General Infirmary for minor injuries.
Anyone who witnessed the collision or has any further information is asked to contact the police via 101, quoting reference 13170416632.