Instead of following his siblings when they all sneak out to play, the Poky Little Puppy lags behind to observe other things. In the beginning, his independence is rewarded. The puppies had all dug a hole underneath the fence to escape from their yard, but only the Poky Little Puppy's siblings are caught. The Poky Little Puppy avoids punishment because he's off exploring as his mother scolds his siblings, and he comes home alone after everyone is asleep. The Poky Little Puppy then eats the rice pudding that the mother was planning to give all the puppies but withheld because of the fence-digging incident. This pattern then repeats itself, only with chocolate custard for dessert instead of rice pudding.
Only at the end of the book does fate catch up with the Poky Little Puppy. When the puppies are sent to bed without dessert a third time, they wait until they think their mother is sleeping, then sneak out of bed and fill in the hole they'd dug under the fence. She sees them doing this and rewards them with strawberry shortcake. The Poky Little Puppy not only arrives too late to get any strawberry shortcake, but is forced to squeeze between the fence boards since the hole has been filled in. The book concludes with Poky Little Puppy going to bed without a bite and feeling "very sorry for himself."