We first see Mary Poppins sitting up on a cloud, powdering her nose.
After the call for "The Perfect Nanny" from Jane and Michael Banks, Mary flies down from the sky to the home of the Banks family.
Mary then discusses her terms of employment with Mr Banks.
After cleaning up the toyroom, Mary takes Jane and Michael out for a walk and they meet Bert. The four of them jump into the chalk pavement picture that Bert has drawn and Mary and Bert have a "Jolly Holiday" dancing with penguins.
They meet up with the children and participate in a horse race.
After an excursion to the bank with their father, Jane and Michael are taken home by Bert, and they attempt to clean the chimney. They are pulled up on the roof and Mary and Bert are forced to follow.
The children solve their problems with their parents and so Mary is no longer needed at the Banks' home so she regretfully leaves.