The accident happened yesterday afternoon.
Three cars were involved and there was a head-on collision north of Lindshammar, at the county border with Kronoberg.
According to the police, it must have been slippery at the scene.
Four people were affected and three of them were taken to hospital for treatment, where one has minor injuries.
Two of them, a woman and a man in their 60s, both have life-threatening injuries.
A car driver in the accident is suspected of negligence in traffic and causing bodily harm.
The accident occurred on the same stretch of road on which three young people died after a head-on collision in September 2021.