A group of parents seeking to overturn Mayor Bloomberg’s ban on cell phones in city schools is likely to appeal a state Supreme Court judge’s decision yesterday to dismiss their lawsuit against the city.

The group’s lawyer, Norman Siegel, said he was disappointed, but vowed to continue to fight the city over the ban, which he has argued is unconstitutional.

“It’s not over yet,” one of the eight plaintiffs in the case, Ellen Bilofsky, said. “It’s still an unfair and unenforceable rule, and we intend to keep fighting against it.”

Ms. Bilofsky said she was compelled to join the lawsuit after the terrorist attacks of September 11, 2001. Her daughter, Jessica — then a 14-year-old freshman at Stuyvesant High School — that day wandered for hours around Manhattan unable to contact her parents because she didn’t have a cell phone at the time.

Ms. Bilofsky’s son, Alexander, is now a sophomore at Stuyvesant, and she said she constantly fears for his safety when he doesn’t carry a phone.

“I don’t want to ever be in that position again. … The Department of Education could not protect her,” Ms. Bilofsky said of her daughter. “If they are not able to protect the students, I don’t think that they have the right to tell parents not to do what they can to protect their children.”

In the lawsuit, the plaintiffs had argued that the ban on the possession of cell phones violates the constitutional rights of students, although they had conceded that a ban on the use of phones in schools was justified. They have been supported by dozens of City Council members, along with the teachers union.

The city’s Law Department hailed the decision by the judge, Lewis Bart Stone, rendered in a 50-page ruling released last night. In the ruling, Mr. Stone upheld the Department of Education’s authority to set the ban — although at one point the judge wrote that the “court may feel a different choice would have been better.”

“The Court correctly held that the Department of Education had a rational basis to adopt its Cell Phone Policy and that the policy does not violate any constitutional right of students or their parents,” a lawyer for the city, Eamonn Foley, said in a statement. The Department of Education, he continued, “is pleased that the policy, which helps foster a productive learning environment among students, will remain in place.”

In the court papers, Mr. Stone dismissed the plaintiffs’ argument that the ban on possession is more disruptive than a ban on use, noting that teachers would have to replace security guards in enforcing it.

“Under a use ban, cell phones will be carried by teenagers and tweens (and maybe even younger children) whose self control may not be perfectly formed,” the judge wrote.

Students at many schools have said they defy the ban by keeping their phones stowed out of sight in pockets and purses. Others reportedly pay delis and other shops outside their schools to keep their phones while they are in school.

The city has sought to reach a compromise with opponents of the ban with a proposal to build lockers outside schools where students could pay a small fee to store their phones during the day — an idea that has been criticized by some parents.

A department spokesman, David Cantor, said several private vendors had expressed interest in building the lockers and that the department had “an eye toward implementing a pilot program in the next school year.”

Mr. Siegel found a partial victory in a section of the ruling called “special circumstances,” in which the judge noted that the school chancellor’s ban on cell phones applied only when there was “no authorization.” The judge wrote that “each school’s principal may address specific situations” and authorize some students to carry phones if necessary.

Still, Mr. Siegel said the group was “seriously” considering submitting an appeal this month.

“The parents want to fight, and so we will,” he said. “We will not rest until it is lifted.”