​From the moment he wakes up with gum in his hair, things just do not go Alexander's way. Getting out of bed, he trips on a skateboard and drops his sweater into a sink full of water. At breakfast, Alexander's brothers Nick and Anthony reach into their cereal boxes and pull out amazing prizes, while all Alexander ends up with is cereal.



​On the way to school, he doesn't get the window seat in the carpool. At school,his teacher doesn't like his drawing of an invisible castle (which is actually just a blank sheet of paper) and criticizes him for singing too loud and leaving out 16. His friend Paul reduces Alexander to third best friend and there is no dessert in his lunch.



​At the dentist's, the dentist tells Alexander he has a cavity, the elevator door hurts his foot, Anthony pushes him into the mud, Nick calls him a crybaby for crying, and Mom catches him in the act of punching Nick.



​At the shoe store, they're sold out of Alexander's choice of sneakers (blue ones with red stripes), so Mom has to buy him plain white sneakers, which he'll refuse to wear.



​At Dad's office, Alexander makes a mess of things when he fools around with everything there (the copying machine, the books, and the telephone) getting to the point where Dad tells him not to pick him up from work anymore.



​At home, Alexander's bad day is far from over. The family has lima beans for dinner (which he hates), there is kissing on TV (which he also hates), bath time becomes a nightmare (too hot water, soap in the eyes, and losing a marble down the drain) and he has to wear his railroad train pajamas (he hates his railroad train pajamas).

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​At bedtime, Alexander's nightlight burns out, he bites his tongue, Nick takes back a pillow, and the family cat chooses to sleep with Anthony. No wonder Alexander wants to move to Australia. The book ends with his mother's assurance that everyone has bad days, even people who live in Australia.