Police are appealing for information from the public after two men were wounded in a public place shooting at Riverstone on Wednesday (March 3) morning.
Just after 9.30am, a taxi driver and his passenger attended Hawkesbury Hospital in Windsor with gunshot wounds, police said.
Authorities were told the taxi driver had earlier picked up the man from a home in Sydney's west.
Police said on Wednesday it was believed the pair were injured after stopping at an address in Riverstone.
The passenger, a 30-year-old man, suffered multiple wounds.
The taxi driver, about 40 years of age, then drove to Hawkesbury Hospital where both men were treated for gunshot wounds. They remained in a serious condition on Wednesday afternoon.
Officers from Hawkesbury and Quakers Hill Police Area Commands established crime scenes at Riverstone and Windsor, which were being examined by specialist forensic police.
The matter was referred to the State Crime Command's Criminal Group Squad, who commenced an investigation.
Anyone with information is urged to contact police or Crime Stoppers on 1800 333 000.