* Percy Jackson & the Olympians series (5 books)
* Heroes of Olympus series (5 books)
* Trials of Apollo series (5 books)
* Magnus Chase and the Gods of Asgard series (3 books)
* The Kane Chronicles series (3 books)
* The Demigod Diaries (1 book)
* The Son of Neptune (1 book)
* The Mark of Athena (1 book)
* The House of Hades (1 book)
* The Blood of Olympus (1 book)
* The Hidden Oracle (1 book)
* The Dark Prophecy (1 book)
* The Burning Maze (1 book)
* The Tyrant's Tomb (1 book)
* The Tower of Nero (1 book)
* Percy Jackson and the Olympians: The Lightning Thief (graphic novel)
* Percy Jackson and the Olympians: The Sea of Monsters (graphic novel)
* Percy Jackson and the Olympians: The Titan's Curse (graphic novel)
* Percy Jackson and the Olympians: The Battle of the Labyrinth (graphic novel)
* Percy Jackson and the Olympians: The Last Olympian (graphic novel)
He has also written 2 books under the name Sterling Frost:
* The Red Pyramid (2010)
* The Throne of Fire (2011)
This count includes novels, graphic novels, and books in the *Percy Jackson & the Olympians* series.