"This is what we ask publishers and writers, you are aware of the vetting code, so censor pages which are likely to create a dispute," conservative minister Mohammad Hossein Safar Harandi told a news conference.
He said publications should be in line with the system's "religious, moral and national" sensitivities and warned writers against graphic descriptions of relationships or sex.
"It is a clear violation of the law to give an excessive portrayal of a man and woman's private relationships … and subject our youth and adults to descriptions of intercourse," Safar Harandi said.
"Or if anyone makes fun of religion, be it Islam or Christianity," he added. "We should not allow opposition to God to be reflected in the media."
All publications in Iran must be approved by the ministry of culture and Islamic guidance, and publishers have complained of tighter censorship on new books since President Mahmoud Ahmadinejad came to power in 2005.
Safar Harandi was commenting on a recent letter by Tehran Publishers' Association who accused his ministry of employing a prolonged and arbitrary vetting process.
"The publishers complained about the lack of a clear law to define the red lines, revoking of publication permits and books being lost when submitted for screening," ISNA news agency said.
"It has been frequently seen that an issue which has resulted in a book being banned is abundant in another one that is published," the letter said.
Iranian publishers depend on state-subsidized paper for their books, which hardly top 5,000 copies in a first edition in most cases.
In the past two years, several new titles and reprints have been banned including the latest novel by celebrated Colombian writer Gabriel Garcia Marquez, "Memories of My Melancholy Whores."
Works of one of Iran's greatest contemporary writers, Sadegh Hedayat, have also been subject to bans, including his widely acclaimed "Blind Owl" and several short story collections.
