Some recent statistics in Iran illustrate the fact that religious books have the highest rank compared to books on other disciplines, but the trend was not the same in pre-1979 Revolution periods. The paper aims to show the growing number and the domination of religious books in the book publishing industry in some pre- and post-Revolution periods in Iran. The geographical distribution of Iranian publishers, the provinces that have the highest ranks after Tehran in the Iranian book publishing industry, the languages and subject distribution of Iranian books are among the issues discussed. Some comparisons are also made between religion and two other disciplines: literature and technology, that are the closest rivals of religion. The paper observes a balance between the three subjects:
religion, literature, and technology as the Revolution settles down, and predicts that the three subjects probably will continue to be the three highest subjects among other disciplines.