School officials, as well as Mayor Michael Bloomberg, have called the phones a distraction and say they could be used for nefarious purposes, including cheating.
Parents insist they need to stay in touch with their children in case of emergencies like Sept. 11. They call the ban irrational and unsafe and say it intrudes on their right to determine what is best for their children.
City lawyers argued that education officials had the right to make policy decisions - "the kind government officials make all the time" - about devices students may have at school.
The state Supreme Court's Appellate Division agreed. It said that nothing about the ban interferes with any of the rights claimed by the parents, nor does it prevent students and their parents from communicating before and after school.
"We are extremely disappointed," said Norman Siegel, lawyer for the parents and students. "We strongly believe the ban is unconstitutional and illegal, and we will not rest until the prohibition is reversed."
The ban came about as New York stepped up its scrutiny of what gets in and out of schools - a policy aimed primarily at finding weapons. Along the way, schools confiscated thousands of cell phones. Students responded by sneaking phones inside their lunches and under their clothes, or paying neighborhood stores small fees to hold their phones during the day.
New York has more than 1,400 schools and 1.1 million students.
"We believe that the court correctly concluded that the objections to the cell phone policy raised issues for the chancellor's consideration, rather than for the courts," city Corporation Counsel Michael Cardozo said in a statement. "Moreover, the policy does not violate the constitutional rights of students or parents. It is an important and 'reasonable' measure to 'maintain order in the schools,' as the court found."
"The Department of Education is gratified that the policy, which encourages a productive learning environment among students, will remain in place," the statement added.
