Nigrita the tortoise conceived with her 54-year-old toy boy Jumbo late last year.
Her eggs were held in a special incubator at Zurich Zoo before nine baby tortoises hatched successfully between February and April, the zoo said in a statement on Tuesday.
Nigrita arrived at the zoo in 1946 and was thought to be around ten years old at the time.
The 100 kilogram tortoise was a late starter where motherhood was concerned, producing her first young in 1989.
In the 27 years since then the tortoise has produced around 300 eggs and hatched 91 babies.
Zurich Zoo is the only place in Europe where Galapagos giant tortoises are bred. The resulting young are given to some 15 institutions across the continent.
An endangered species, Galapagos giant tortoises can live for more than 100 years, making them the longest-lived of all vertebrates, according to National Geographic.
After mating, a tortoise buries her tennis-ball-sized eggs in the sand, and young hatch some four months later.
The tortoises reach sexual maturity at around 25 years old and continue to grow until they are 40.