Emergency services were called to the junction of the A449 and A450 Worcester Road, in Torton, near Kidderminster, at around 3pm on Sunday.
One man, 18, suffered serious injuries and was taken to hospital. He was a passenger in one of the vehicles involved.
West Mercia Police officers are now appealing for witnesses to come forward after the crash involving a black Renault Clio and a blue Mitsubishi.
The driver of the Clio, an 18-year-old man from Birmingham, was arrested on suspicion of causing serious injury by dangerous driving and drug driving. He has since been released under investigation.
A West Midlands Ambulance Service spokesman said: “We were called at 3.06pm on Sunday to the junction of the A449 and A450, in Kidderminster, to reports of a three-car road traffic collision. An ambulance, paramedic officer, a MERIT trauma doctor and two critical care paramedics attended.
“One occupant, a man, suffered serious injuries in the collision and received trauma care by the team of medics at the scene before being transported on blue lights to Queen Elizabeth Hospital Birmingham for further emergency treatment.”
A West Mercia Police spokesman said: “Officers are appealing for witnesses following a collision near Kidderminster on Sunday, November 29.
"The collision, which happened at just after 3pm on the A449 Worcester Road at its junction with the A450, involved a black Renault Clio and a blue Mitsubishi Colt.
"The rear passenger in the Renault Clio, an 18-year-old man, suffered serious potentially life changing, injuries.
"The driver of the Clio, an 18-year-old man from Birmingham, was arrested on suspicion of causing serious injury by dangerous driving and drug driving. He was released under investigation while enquiries continue."
Anyone who witnessed the crash, or has dash-cam footage, is urged to call West Mercia Police on 101, quoting incident number 326i of November 29.