At about 2am, police were called to the intersection of Folkestone and Morphett Roads after reports that three males had assaulted the driver and stole cash from the taxi.
He did not suffer serious injuries.
The three suspects are described as all being of Aboriginal appearance and aged in their late teens, all of them between 176-178cm tall with two of the suspects wearing black jumpers (one hooded jumper) and the other a white jumper with black markings on it.