A European advocacy group has ranked New Zealand 158th out of 165 countries on children's rights.
Children's Commissioner Andrew Becroft said the ranking was "a wake-up call" for New Zealand to protect children better from abuse and neglect and to give children a say on new laws and policies.
"There is a startlingly weak commitment in New Zealand to factoring in children's voices into our policymaking," he said.
But Canterbury University political scientist Professor Bronwyn Hayward, who specialises in child and youth politics, said the new index was "the most bonkers ranking I've ever seen".
"There is no way we could compare the situation facing children in Ethiopia, where I have just been, it's a completely different context from the situation facing children in South Auckland, for example," she said.
Ethiopia is ranked 137th on child rights, ahead of New Zealand. The rankings are topped by Portugal, Norway and Switzerland.
The list, published yesterday by the Amsterdam-based Kids Rights Foundation, measures 23 indicators in five fields.
New Zealand ranks 17th for life expectancy and child mortality, 26th in educational participation, 36th on health measures such as immunisation and sanitation, and 37th on protecting children from child labour and teen pregnancy.
But it ranks bottom-equal in the world on "child rights", with the lowest-possible scores for non-discrimination, best interests of the child, respecting children's views, enabling legislation, budget resources, and data collection.
All the "child rights" measures were taken from reports of the United Nations Committee on the Rights of the Child. New Zealand's ranking dropped from 45th last year to 158th because of negative comments on all child rights issues in the UN committee's latest report on New Zealand last September.
The committee's negative comments on discrimination and the best interests of the child were about Māori and Pacific children, calling for "urgent measures to address disparities in access to education, health services and a minimum standard of living by Māori and Pasifika children and their families".
It marked New Zealand down on respecting children's views particularly because of recent family law changes which don't give children a say when their parents split, unless dispute resolution fails and the case goes to court.
On legislation, the committee called for "a comprehensive children's code" and ensuring that all new laws complied with the UN Convention on Children's Rights.
On budget issues, it proposed "a tracking system covering all child-related expenditures", and on data it called for figures on "all areas of the Convention" including child poverty - an issue where the Government has refused to adopt an official measure.
Becroft said a working group was close to finalising a system of "child impact statements" for new laws and policies, but it would be voluntary.
"I think, and the UN has made this clear, it should be mandatory to take into account children's views in policy formulation," he said.
Minister for Children Anne Tolley said the Government was committed to ensuring children's rights, which is why it was "completely overhauling our care and protection system".
"Legislation passed in December 2016 now ensures children and young people's views are taken into account as part of decision-making at an individual level and in the development of services and policy [in the child protection system]," she said.
"It also supported the establishment of an independent advocacy service called VOYCE - Whakarongo Mai.
"As part of the second major piece of legislation currently before the House, we are establishing enhanced complaints processes for children, young people and their families, whānau and caregivers. This is in addition to separate work on a transparent independent complaints body.
"The Ministry of Social Development is also leading an ongoing, cross-sector, work programme to improve children's rights in New Zealand based on recommendations made by the Committee on the Rights of the Child last year."