Frankie Muniz plays Jason who is a high school student. His biggest problem is his life is built on small or big lies that puts him into trouble most times. However, he cannot escape from his teacher and he finishes his creative writing homework just before its deadline. While he is biking fast to hand his homework to the teacher, he crushes into a car. As he explains the situation to grumpy man(Giamatti) in the car, he gives him a lift to his school. But the problem is Jason leaves his homework in the car, the other way of saying this is Marty Wolf(Giamatti) steals it.

After a few months Jason goes to a movie and sees a trailer that takes him aback. Because the story of the movie is based on his homework. He tells that to his parents but of course they don't believe him. Especially his father uses words which insults him. Jason decides to go to LA and find Wolf to tell his father that Jason is not a liar. When Wolf refuses it, Jason takes action and ruins his life.

This is the short story of the Big Fat Liar. Well, as a kids movie it might be a light hearted one but there are some errors that even could would ask if that is possible. Such as, having such a small amount of money and going to LA with a friend to sort the problem out, having access to this cinema producer's highly protected house and office, setting up a telecommunications system overnight.Does it seem believable? It does not. Well this is a kids movie but kids are not that gullible.

Big Fat Liar offers some little pleasure to its target audience. Unfortunately, I am not a big fat liar to say that this is a good movie. ** out of *****