Marmaduke lives in full-fledged family, has a good time with all the heart and amuses kids. However every time when the family suits a weekend and invites on a visit friends, this dog literally destroys ready tables and destroys everything that sees on the way. It even got on pages of local magazines and also to television where told about his awkwardness and infinite troubles which it brings to the owners. It was seen by the professional trainer. He is sure that he will manage to improve situation of this family and also to teach a dog to professionalism and to send to a competition of champions.

Starting study, the trainer does everything possible to force Marmaduke to work according to the plan. But it became clear, as he cannot make similar. Time of a competition approached closer and closer and when they went to the championship where all dogs stood in the row, the main character found a table with entertainments for people, and ate all. Then, naturally, could not even move on the racetrack. Owners are madly upset, they do not know at all what to do with this dog, and even on the advice of people around decided to withdraw its candidacy from the Championship. But later Marmaduke realized that it is necessary to try to please local inhabitants and to be closer to society, having bypassed competitors.