The collision occurred near the Duke William Pub in Callow Hill on the A456, at approximately 10.15pm.
A blue Ford Focus and a black Audi A7 were involved in the crash.
The Ford Focus was travelling towards Kidderminster and the Audi A7 towards Rock when the collision happened.
Tragically, three people in the Ford Focus were pronounced deceased at the scene: a 32-year-old woman, a 28-year-old woman and a four-year-old boy.
The three people in the Audi were taken to the Worcester Royal Hospital with minor injuries.
Inspector Stephanie Arrowsmith, operations policing unit said “First and foremost our thoughts are with the loved ones of the people who died in the collision.
"I would like to appeal to anyone who witnessed the collision or has any information or dash-cam footage which may help with the investigation to call the investigating officers.
"The road is currently closed as officers carry out enquiries into the collision, we anticipate the road to be closed until later this afternoon (Thursday).
"Anyone with information can contact the police on 101 extension 770 2273 or by email:- email@example.com."
West Midlands Ambulance Service was called at 10.17pm and sent four ambulances, two paramedic officers and the Trust’s Hazardous Area Response Team (HART) to the scene.
A spokeswoman for the ambulance service said: “On arrival, crews discovered two cars had been involved in a collision.
“Sadly, it quickly became apparent that the two adults and child who were in the first car could not be saved and they were confirmed dead at the scene.
“A woman and two children from the second car were treated by ambulance staff for injuries not believed to be serious before being taken to Worcester Royal Hospital for further treatment.”
West Mercia Police say the A456 is likely to remain closed for the next two days due to the severity of the crash.