The attack happened on Tuesday during the morning rounds in which the animals are fed and treated with insect repellent, Salzburg Hellbrunn Zoo director Sabine Grebner told a news conference.
“We do not know exactly how it happened,” Ms Grebner said.
The woman died at the scene after suffering chest injuries. Her colleague, who was also reportedly her husband, was rushed to hospital with a broken femur, local television news outlet Oe24 reports.
Ms Grebner said of the woman: “She was very careful and thoughtful with the animals and she had an extremely good feel for animals.”
The 33-year-old was assigned to smear the rhinos with an insect stick because the animals are very sensitive to insect bites, Oe24 reported Ms Grebner as saying.
The victim, a German from the state of Bavaria, was very experienced and specialised in rhinos, while the man, aged 34, was in charge of animal feed.
The rhino involved was a female called Yeti, Ms Grebner said, adding that all the rhinos at the zoo have been there a long time and are cooperative with their keepers.
The southern white rhino was born in South Africa in 1999 and has lived in Salzburg since November 2009, according to the Rhino Resource Centre.
The zoo is home to 150 species and around 1,500 animals. It remained closed on Tuesday.