Maxine Mane has not been in touch with her family since she left her Rotorua home with a sports bag, all her clothes, and a blanket last Thursday.
Detective Sergeant George Staunton said it was believed Maxine had run away from home.
"Maxine only moved to Rotorua from Auckland in January and she is not very familiar with this area," he said.
"That fact, combined with her young age, means that we do have concerns for her wellbeing and both her family and police are keen to find her as soon as possible."
Maxine is of Maori descent, about 160cm tall, of medium build and has long brown hair.
Police would like to hear from anyone who knew where she was.