Three young men were taken to hospital after the car in which they were travelling struck a tree.
Three occupants of a black Vauxhall Astra – all men aged 18, 19 and 23 – were injured and taken to hospital.
The 18-year-old had to be cut free from the vehicle by the fire service and suffered serious pelvic injuries.
The smash happened just before 9pm on Tuesday on Broom Lane in Rotherham,.
Police are appealing for witnesses to the smash and say the car was travelling from Rotherham towards the roundabout on East Bawtry Road and was on the wrong side of the carriageway when the collision occurred.
It is believed another vehicle was travelling with the Astra but did not stop.
n Call police on 101 quoting incident number 1147 of 29/07/2014.