A man was rescued by firefighters on the A41 near Waddesdon after a crash involving three cars and a lorry.
The fire engines and a first response vehicle were deployed from Aylesbury fire station just before 9am.
The road was closed but has since re-opened.
The fire service said a girl was injured in the collision but was not trapped.
An ambulance service spokesman said: “We were called at 8.38am with the caller reporting a three vehicle collision at the junction of Rose Terrace and Baker Street – the vehicles having rear-ended each other.
“We currently have an officer and an ambulance crew at the scene, and another ambulance arriving shortly.
“There are six patients with a variety of mainly minor injuries who are currently being assessed.”