One was a collision between a car and truck in Wyndham Rd, Tuturau, near Mataura about 8.55am.
Late afternoon, a police spokeswoman confirmed it was the sixth crash reported since Wednesday morning.
A St John spokesman said one person suffered moderate injuries and was taken to Southland Hospital in Invercargill.
There were five reported crashes in the region on Wednesday, including a car which hit a pedestrian in Invercargill.