The book tells of Harry Potter's second year at Hogwarts School of Witchcraft and Wizardry, where messages written in blood begin to appear on the walls, warning that the Chamber of Secrets has been opened and that the "Slytherin heir" will kill all students which do not come from a witch family. In addition to the messages, several students begin to appear petrified. Throughout the year, Harry and his friends Ron Weasley and Hermione Granger investigate these attacks that had also occurred years before, which leads the protagonist to learn the story of his greatest enemy, Lord Voldemort, who had killed his parents when was a baby.
The book was published in the UK on July 2, 1998 by publisher Bloomsbury and the United States on June 2, 1999 by Scholastic Inc. In Brazil, the publisher Rocco published the book in August 2000, and in Portugal on January 17, 2000, by Presença. Although Rowling has found it difficult to finish the book, he has won praise and critics awards, for young readers and the publishing industry, though some critics have found the story a little frightening for children. Like the other novels in the series, Harry Potter and the Chamber of Secrets sparked off some religious debates, religious authorities condemned the use of magical themes while others praised their emphasis on self-sacrifice and the way a person's character results in their choices. Several commentators have noted that personal identity is a strong theme in the book, and that it addresses issues of racism through Muggle (non-witching) treatment. Some commentators regard the diary as a warning against the unconcerned acceptance of information from unreliable sources that can not be verified. Institutional authority is portrayed as selfish and incompetent. The book is also known to have links to the sixth novel in the series, Harry Potter and the Half-Blood Prince.
The film adaptation of the novel, released in 2002 and directed by Chris Columbus, became (at that time) the seventh highest grossing film in history, receiving favorable reviews. Electronic games based on Harry Potter and the Chamber of Secrets were also released for various platforms, and many of them received favorable reviews.