Facial piercings have been approved as part of school uniform at a major New Plymouth high school.

New Plymouth Girls High has abandoned an old policy allowing students one stud earring in each ear - a rule still imposed by at least four other Taranaki secondary schools, the Taranaki Daily News reported.

School board chairman Darren Muggeridge said students would now be allowed one lip and one nose piercing.

He described the new rule as a compromise in a hard-to-police area.

"It's sort of meeting the students, not necessarily halfway but a little bit of the way for them to still wear a piercing but still sit within some rules and there are still rules around what is worn and where they're worn."

Mr Muggeridge said the school had tried to be very strict around uniforms, but it took a lot of time and effort to manage piercings.

But David Hodge, principal of the country's largest school Rangitoto College, said he was seeing demand for more conservative dress codes.

His school did not allow facial piercings and had introduced a more conservative uniform in 2010 with backing from the community, he said.

"A lot of the pressure seems to be coming from that direction. There's a huge pressure on teenagers to succeed academically and that's bringing a great degree of conservatism.

"We've got more applications for enrolment than we can handle even though we are a 3000 pupil school - so we've probably got it right."

However, the culture may be different in New Plymouth, he said.

"New Plymouth is not Auckland so maybe they have a different world down there.

"The wishes of the community will be naturally different for different schools."

Acting Principal of New Plymouth Girls High Stella Bond told the Taranaki Daily News the new policy had been decided after lengthy debate.

She acknowledged it may not satisfy all parents, but said policing facial piercings was no longer worth the time and effort the school had put into it.

"If we're spending too much time on something, we need to decide if it's worth it. We think there's much more significant things to be dealing with.

"We're talking a stud the size of an old metal pin and when you're talking that level of invisibility and trying to draw a line it's a case of thinking maybe it's time for a shift."

Ms Bond said it has been four years since a significant change was last made to the school's uniform.