The tiger's name is Martha and Tuesday, the Siberian tiger was exploring her new home after being donated by a Nebraska zoo.
Since the Christmas 2007 attack the San Francisco Zoo has installed a higher wall and made the tiger grotto more secure.
"We added 10 feet or more to the height of the enclosure, additional hot wire and some viewing windows and the mesh that you see out there," Carnivore Keeper Debbie Marin said.
Despite Tuesday's rain, visitors seemed excited about Martha's arrival.
She weighs almost 300 pounds and her diet consists of mostly chicken, rabbits and pork.