The Mystery of the Sintra Road was initially published in Diário de Notícias, in the form of 66 letters to the editor that were reproduced in the serials section of the newspaper between July 24 and September 27, 1870.

It was published as if it were a true story about an alleged kidnapping (with the knowledge of the newspaper's editor, Eduardo Coelho, who was a friend of Eça's family).

The bet Coelho made with the two authors that only the last instalment would reveal to the readers the writer's identity was very successful.

It captured the imagination of and even frightened the people of Lisbon, many of whom thought it was describing true events, and resulted in copies of the daily paper being sold out.

The text was heavily reworked by Eça de Queirós prior to publication of the third edition, such that he was the lead author for the book version, whereas Ortigão's name had come first at the end of the serialization.

[1][2][5] Beginning in January, 2017 Diário de Notícias re-issued the novel as a serialization of 20 instalments, based on the third edition of the book rather than the original newspaper version.

While the book does include passages of excessive Romanticism that sound bloated to contemporary ears, it is an exciting story in which the characters "are flawed and pathetic without being pitiable.