The Browns are a family with seven children. The widowed father is overwhelmed with his children and is therefore a nanny ( "Nanny") after another. But once it is already 17 children were girls, are the children and the leader, the oldest son, Simon, immediately agreed that the number 18 does not stay long. Since decides to Nanny McPhee, the family to visit. After she ties with the magic firmly in the grasp, it takes care of a new woman for Mr. Brown, the cunning concerns of bright aunt Adelaide and the secret service of the girl and thereby slowly wins the heart of the Brown children.