An 11-year-old boy is in hospital in a stable condition after being mauled by a sea lion at a Sydney zoo.

Jack Lister had been chosen as a member of the audience to take part in the Sea Lion Show at Taronga Zoo in Sydney yesterday.

The zoo says after the show the boy "accidentally strayed into an area behind the female animal".

It says the sea lion then "reacted unexpectedly with severe fright, and turned and bit the boy".

The boy was treated on site by first aid officers, then taken by ambulance to the Children's Hospital at Randwick last night for surgery on a series of puncture wounds.

The zoo says "the animal has a long history of participating in animal encounters and has never displayed aggressive behaviour" before.

The audience participation element of the seal show has been suspended until an investigation into the attack has been completed.