A woman who insisted on seeing the presumably lifeless body of her premature baby found the infant alive in the drawer of a hospital mortuary.
Authorities say the girl had spent 12 hours in the refrigerated room at the Perrando de Resistencia hospital in northern Argentina.
Analia Bouter told Todo Noticias television that she thought she was hallucinating when she looked at her baby in the mortuary drawer, then heard a whimper and saw signs of life.
Doctors say the girl is now in good condition.
The baby was born on April 3 after just six months of pregnancy, and the hospital issued a death certificate, saying she died of unknown causes, Ms Bouter said.
She said doctors told her that "nobody knows how she could have survived 12 hours in a refrigerated room".
Rafael Sabatinelli, deputy health secretary of Chaco province where the hospital is located, said authorities were investigating those involved in the incident.