The story tells of a fish with shiny, multi-colored scales named Rainbow Fish. He is always fond of his scales. But one day, a small fish asks him if he could have one. Rainbow Fish refuses in a very rude way. The other fish are really upset about his behaviour and don't want anymore to play with him.
Feeling upset, his only friend left, the starfish, tells him to go visit the mysterious octopus for advice. Rainbow Fish finds the octopus and asks what he should do. The octopus tells him that he should share the beauty of his scales with his friends.
When he encounters the small fish a second time, the Rainbow Fish gives him one of his precious scales and, seeing the joy of this little fish, feels immediately much better. Very soon Rainbow Fish is surrounded by other fish requesting scales and he gives to each of them one of his shiny scales.
The author about his book: "Rainbow Fish has no political message. The story shows us the joy of sharing. We all enjoy to make presents for Christmas or birthdays and we are feeling good doing so. I want to show to our children the positive aspect of sharing: To share does not only mean to give away something (what is quite hard for a child), but above all to make happy someone else - and itself.