Less than a third of schools have effective science programmes for Year 5 to 8 students, according to the Education Review Office.
An ERO report, Science in The New Zealand Curriculum: Years 5 to 8, found that only 27 percent of 100 schools reviewed last year have effective or generally effective science programmes for Years 5 to 8 students.
ERO chief review officer Dr Graham Stoop said children are not being given the "best opportunity to build on their excitement about discovering the world around them".
"We need to improve the way we teach science to our young children to help them succeed in an economy increasingly based on knowledge and innovation."
Dr Stoop said the report was one of a succession since 2004 which have looked into the teaching and learning of science in primary schools.