On the day which marked the end of WW-I Mr Button's wife dies in childbirth. The child has all the features of an old man. So he thinks that a child is a monster. But because he's promised his wife that the child will be safe he does not kill him. Instead he keeps him outside in an old-age home. The caretaker of the old-age home adopts him and names him Benjamin (BP).

Everyone expected him to deteriorate and die, instead he grows. While everyone around him is growing old, he is growing younger. He falls in love with Daisy - the granddaughter of one of the old ladies. Soon he moves out of home and travels the world. He comes back after the end of WW-II. From then on its about Daisy and Benjamin's love for each other.

Will they be able to live happily ever after?