The pair were found by a passerby in the Brazilian city of Curitiba, who called the police and officers came and collected the twins.
When they were found the babies still had their umbilical cords attached, and medics say they were abandoned almost immediately after being born.
Hospital staff named the girls Eloa - which means God - and Heloisa - ‘warrior woman’.
One of the women who found them told reporters: ‘I thought they were a dog and when I looked at them I realised they were two babies.’
The babies will remain in hospital until they begin gaining weight, when they will go into care where they will be made available for adoption.