Police, ambulance and fire were called to a two-vehicle collision on the A390 at Callington at noon on Wednesday 5 July.
The head-on collision involved a Peugeot Boxer van and a Peugeot 206.
A 2-year-old child has sustained a potentially life-threatening head injury.
Air ambulance has taken the casualty to Derriford Hospital for initial treatment; the boy is expected to be transferred to Bristol hospital, along with his family.
The road remains closed to allow the Serious Collisions Unit to undertake scene investigation work. Vehicle recovery is expected to take place later this afternoon.
Anyone who witnessed the collision is asked to contact the police on [email protected] quoting log number 393 for the 5th of July.
Source:: Devon and Cornwall Police News