Emergency services attended multiple crashes in Clinton, Owaka, Balclutha, Dunedin and Waikouaiti between 8am and 9.30am.
Senior Sergeant Dave Scott, of Dunedin, said wet roads coupled with a late frost caught out motorists and pedestrians.
''We were saying to people to leave a bit later for work and be aware that the roads might look just wet, but there is black ice everywhere.''
Emergency services attended eight crashes, including a 4WD roll-over on SHI, near Waihola, and a commuter bus sliding into a parked car in the Dunedin suburb of Concord. The crashes resulted in only minor injuries, he said.
Police urged motorists to watch their speed and following distances.
A Southern District Health Board spokesman said six people with minor injuries went to Dunedin Hospital after ice-related incidents.
