The Education Review Office says the majority of primary schools are not teaching science effectively.
The office conducted a survey in to how science is being taught, and found only a quarter of schools are doing so properly.
ERO chief review officer Graham Stoop says schools are giving priority to other areas of the curriculum at the expense of science.
Mr Stoop says there is also a lack of teacher confidence and capability in science teaching, and limited opportunities for professional development in the area
"We also suggested that perhaps we might need to explore the quality of initial teacher education in science teaching."
Mr Stoop says the Office is working with the Ministry of Education to put a greater emphasis on science.