After a meeting with editors on Monday, the king was reported in the Saudi media as saying that "one needs to think if he would want his daughter, sister or wife to appear like that. Of course, no one would".
Newspapers have recently broken with tradition and published pictures of women with hair covered but faces showing.
They had also begun to debate women's issues, such as being forbidden to drive and vote.
"Young people are driven by emotion and the spirit, but the spirit can go astray. So I ask you to go easy on these things," the king also reportedly said.
Abdullah had been regarded by many Saudis as a quiet reformer who might begin to loosen the strict social codes that govern the conservative Gulf state.
In recent months, however, many figures in the powerful religious establishment have used mosque sermons and websites to criticise any move towards "liberalisation".
The 83-year-old ruler also called on newspapers to stop publishing stories that portray the country in a negative light.
"I ask you to go easy on ... unclear issues based on rumours and not to write things that hurt your country," he said.
Abdullah also advised newspapers to ignore foreign media organisations, especially when their stories are "against Islam or against Arabs".