The Spanish government, Catholic Church and Muslim leaders have joined forces to publish a school textbook on Islam.
The book Discovering Islam - for primary school children - was written in Spanish by a Muslim leader.
Spanish officials say the book has no parallel among Spain's EU neighbours with large Muslim minorities.
Spain has about a million Muslims, out of a 44 million population. The book is aimed at helping Muslim children learn about their faith and integrate better.
Spain's El Mundo news website said the format was similar to textbooks about Catholicism.
A Spanish justice ministry official involved in the project, Jose Manuel Lopez, told the Associated Press that only about 3,500 Muslim six-year-olds were learning about Islam formally in Spanish public schools.
Riay Tatary, the book's author, said the Madrid region still offered no classes in Islam, despite thousands of requests for it to do so.
Spain's director-general of religious affairs, Mercedes Rico, said the book "responds to the aim of normalising the right of parents for their children to receive the religious education they want".
The first run of 15,000 copies was produced by the Catholic publishing house SM.