Police Scotland said the crash happened on the A9 at Cuach, about four miles north of Dalwhinnie, at 6.36pm on Friday.
A black Vauxhall Zafira, a red Audi A3 and a silver Volkswagen Touran were involved.
Officers said two men and a woman were taken to Raigmore Hospital in Inverness for treatment to injuries which are not believed to be life-threatening.
Sergeant Neil MacDonald, of the roads policing unit, said: “Our inquiries into the cause of this crash are ongoing and we are appealing to anyone who was in the area at the time to please get in touch.
“In particular, we are keen to speak to anyone who saw the cars or who may have dashcam footage that can help with our investigation.
“If you can help, please contact us on 101, quoting reference 2819 of 3 December.”