The book was on the shortlist for the Nebula Award for Best Novel. It would also have been shortlisted for the Hugo Award for Best Novel, except that Pratchett withdrew it, as he felt stress over the award would mar his enjoyment of the Worldcon This was the first time Pratchett had been shortlisted for either award.
With great reluctance, Lipwig takes up his duties, only to find things are even worse than he had presumed. The Post Office has not functioned for decades, and the building is literally full of undelivered mail. Two eccentric employees remain: the aged Junior Postman Groat, and Stanley, a pin-obsessed boy who was raised by peas. They are more concerned about following the Post Office Regulations than seeing the postal system restored. There's also a Post Office cat, Mr. Tiddles, but it is even more set in its ways than its owners. Lipwig learns that within the last couple of months, while he was waiting to die in his prison cell, a whole string of newly-appointed Postmasters have met their own deaths in the Post Office building. Lipwig eventually discovers that most of the men were killed by failure to safely interact with a "ghost reality" which overlays the physical structure in the Post Office. A wizard at Unseen University explains to him that this phenomenon is caused by the fact that words have power, and masses of them are currently crammed into every available inch of space in the Post Office.
Passing a cruel and dangerous test conducted by the few surviving members of a secret order of postmen, Lipwig "officially" becomes Postmaster, and also learns that the Post Office was once a very efficient operation. Its downfall was when the trans-dimensional letter-sorting machine, created by the infamous inventor Bloody Stupid Johnson, became so highly tuned (owing to Johnson's substitution of 3 for pi in its design) that it was sorting letters before they were written, along with letters which might have been written, but weren't.
Lipwig introduces postage stamps to Ankh-Morpork, hires golems to deliver the mail, and finds himself competing against the Grand Trunk Clacks line. He meets and falls in love with the tough, chain-smoking golem-rights activist, Adora Belle Dearheart, and the two begin a relationship by the end of the book. Dearheart is the daughter of the Clacks founder John Dearheart, though the company was taken away from her by tricky financial manoeuvring. Because of this, she still has useful contacts amongst the clacks operators.
The unscrupulous Clacks chairman, Reacher Gilt, sets a banshee assassin (Mr Gryle) on the Postmaster, but only manages to burn down much of the Post Office building. The banshee dies when he gets flipped onto the space-warping sorting machine. Lipwig makes an outrageous wager than he can deliver a message to Genua faster than the Grand Trunk can. "The Smoking Gnu", a group of clacks-crackers, sets up a plan to send a killer poke into the clacks system that will destroy the machinery, halting the message that Lipwig will race against. Lipwig talks the Gnu out of it, and opts for a more psychological attack on the Grand Trunk, leaving the semaphore towers standing. This plan succeeds, and Gilt ends up walking through a very specific door - the very option that Lipwig avoided.
The novel is filled with references and parodies about computers and the internet, including GNU, crackers (specifically, phreakers), AT&T, Treasure Island (Gilt's cockatoo), The Great Gatsby (Gilt's parties), Lord of the Flies, and The Lone Gunmen ("The Smoking Gnu").
This will be filmed in Hungary over the summer of 2009
! colspan="3" | Reading order guide |}