Emergency services were called to Mailer St about 3.15pm yesterday following reports of the crash.
Among the four injured was one child, St John said.
Two people received moderate injuries and two others minor injuries.
''Three cars were involved,'' a police spokeswoman said.
''One car has hit the back of the other car ... and the second car has hit a parked car.''
Two tow trucks were required to remove the vehicles from the street.
All four patients were taken to Dunedin Hospital's emergency department.
It was unclear what led to the crash, the police spokeswoman said.
Inquiries were ongoing.
Dunedin police (03) 471-4800, Crimestoppers 0800 555-111.