A 30-year-old woman died of the mosquito-borne disease about a week after a 25-year-old woman in the Noumea area died of dengue type 1.
The authorities have said in both cases they were not at special risk.
A public health emergency is in place as about 700 people have been infected.
60 have been taken to hospital.
The authorities say all neighbourhoods of the city are now affected and more personnel are being hired to try to eliminate breeding areas for mosquitos