Two appliances and crews from Aylesbury attended, along with one officer.
One man, one woman and one boy were out of their car before the firefighters arrived. The woman was suffering shock and bruising, the boy was injured.
The second vehicle contained one man, one woman and two girls. The woman and one of the girls were injured.
The firefighters provided immediate emergency care to those injured, who were then passed into the care of South Central Ambulance Service.
Thames Valley Police were also in attendance.