At about 7.40pm on May 26, a Toyota sedan and a Toyota ute collided on Milperra Road in Milperra.
The sedan rolled, trapping the driver and passengers.
Two of the passengers, a 41-year-old man and a 12-year-old girl, died at the scene.
A third passenger, a 10-year-old boy, was taken to hospital in a stable condition.
The sedan driver, a 52-year-old man, was taken to hospital in a serious but stable condition.
The ute driver, a 19-year-old man, was treated for minor injuries at the scene before he was taken to hospital for mandatory testing.
At about 6pm yesterday, a 52-year-old man attended Bankstown Police Station and was charged with multiple driving offences, including two counts of negligent driving occasioning death.
He was bailed to appear in court on November 6.