Education Minister Hekia Parata says official figures for children taking part in pre-school education are probably inflated.
Figures released this week show more than 95% of new school entrants this year had some form of early childhood education, up slightly on last year.
Participation rose for Pasifika children to 88%, and to nearly 92% for Maori.
However, Ms Parata says those figures are not accurate, because they rely on what parents tell schools and early learning providers have different ways of recording attendance.
She expects percentages to fall in 2015 when the Ministry of Education starts tracking daily attendance by each child.
Ms Parata says the new information system willl give a much more accurate picture of how many children are attending early childhood education and replace paper records at 4500 early learning providers.