Scientists are alarmed as a growing number of schools considering ditching science from the compulsory curriculum because it is too difficult for some pupils.

Schools across the country are pulling the pin on year 11 science, saying the step up from year 10 was too big and students were struggling to achieve NCEA level 1.

The Ministry of Education has established an advisory group after the Secondary Principals' Association warned in recent weeks that more schools would opt to make science elective if the achievement standard was not reviewed.

SPANZ president Tom Parsons said it was vital science was recognised to be as important as literacy and numeracy - and for some students who choose to leave school early, level one was their only exposure.

"The alternative is that they have no knowledge of science at all," he said.

The prime minister's chief science adviser, Sir Peter Gluckman, said schools that gave up on science when faced with struggling pupils were not doing them justice.

"It just seems to me that they are not doing the right thing by young people. To exclude them so early from studying science, you're affecting their future," he said.

"If it's too hard, that would have much to do with improving the way we teach, not the content. That becomes a pedagogical challenge, not a reason to walk away."

But Naenae College principal John Russell said the school dropped compulsory science because it "wasn't accessible for all students" and some teenagers wanted to focus on art and humanities subjects instead.

"Year 11 should be seen as a year of general education and the more it can be kept open the better."

Rongotai College still had compulsory level 1 science but principal Kevin Carter said it had become more difficult for some students to pass.

"No-one wants to see us dumb down the curriculum, but we have to see some level of success."

Tawa College principal Murray Lucas said not everyone could achieve science credits at the current level, so another option needed to be found.

"We don't want kids putting all their eggs in one basket. New Zealand needs people well versed in science at all levels," he said.

But Sir Peter said that science needed attention, not abandonment.

"I believe that society would be well served if there were more young people engaged in science literacy.

"I'm not arguing everyone should become a nuclear physicist - I think everybody needs some level of understanding of issues like climate change, and genetic modification and nanotechnology; these thing are going to impact on these young people's lives."

Malaghan Institute of Medical Research director Graham Le Gros said everyone was bombarded with decisions based on science everyday and it was vital people understood the basics.

"Everyone needs to know how the body works and how the world works ... every human needs to have some understanding of science to be part of the modern world."

Ministry of Education deputy secretary Rowena Phair said an advisory group were responding to principals' concerns about needing to offer science to students of all abilities.

Science as a compulsory subject was decided by a school, not the ministry, she said.

But Mr Russell said the Ministry of Education was pushing vocational pathways for students, which meant some teenagers' education narrowed early.

"It's frustrating to see that door close for some students, because it closes a lot of other doors further down the track."