A four-year-old girl has been taken to hospital after suffering burns to her face and body at a Japanese teppanyaki restaurant in central Sydney overnight.

The girl was with her family at Wharf Teppanyaki, on Lime Street at King Street Wharf, when she was burnt by an open flame about 7pm on Sunday.

Teppanyaki restaurants feature chefs cooking at an open hot plate.

Paramedics treated the girl for burns to her forehead, cheeks and shoulders, before taking her to Sydney Children's Hospital in Randwick. She was in a serious condition, a NSW Ambulance spokeswoman said.

Teppanyaki restaurants allow diners to sit around an open hot plate, as a chef prepares and cooks meals in front of them.