The A34 north of Newbury was closed last night (Saturday) following a collision involving two vehicles.
Two pumps from Newbury were called to the serious incident near East Ilsley at about 10pm, and one from Didcot.
A spokesperson from Newbury fire station said: "There was a total closure. Two cars were involved.
"Two casualties were extricated. Their condition is unknown."
An air ambulance, police vehicles and a police helicopter were also at the scene until around 1am this morning.
Thames Valley Police spokesperson Connie Primmer said: "Police were called at 9.56pm yesterday (Saturday) to reports of a collision involving two vehicles on the A34.
"Two people, both men, sustained serious injuries and were taken to the John Radcliffe Hospital where they are currently still being treated.
"The road was closed until approximately 4am when northbound carriageway and one southbound lane re-opened."
The incident took place on the northbound carriageway and emergency repairs blocked the southbound carriageway this morning before re-opening at around 10am.