A child bitten by her teacher, teachers smacking children and staff smoking near pupils were among almost 250 complaints - including abuse and neglect - at early childhood education centres reported last year.
Information about the complaints to the Ministry of Education were released under the Official Information Act to child advocacy group ChildForum.
The group's national director, Sarah Farquhar, called the results "horror stories" and raised concerns about how complaints were dealt with by the ministry. She felt there was a heavier focus on supporting early childhood education (ECE) services than complainants.
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Dr Farquhar said parents needed to know what went on at their child's centre, and believed the complaint and how it was investigated should be made publicly available.
"People are using services not knowing what its past history has been," Dr Farquhar said. "Parents need to know, 'What am I getting myself into?' and 'What do I need to be aware of?' to ensure it doesn't happen to their child."
Dr Farquhar said increased transparency would protect children.
"Children are very young and are very vulnerable. They are often not believed, and it's a big step for a parent to make a complaint. Quite possibly the complaints that were received were just the tip of the iceberg, and that is really concerning."
Early Childhood Council chief executive Peter Reynolds said most complaints were minor. "The overwhelming majority of ECE centres deliver good services. They are loved and trusted by the families they serve ... There is a small minority which appear not to be up to standard."
Making complaint information public would have to be done carefully, and some information was already available via Education Review Office reports, he said.
The Ministry of Education's deputy secretary for early learning, Rawiri Brell, said children's safety and wellbeing were paramount.
"While individual services are legally responsible for the welfare of children in their care, the ministry treats any allegation of misconduct or negligence very seriously," he said.
"There are over 195,000 children attending ECE services. The vast majority are cared for safely without incident or injury. But incidents can happen and when they do, most are managed effectively by the service," Mr Brell said.
"More serious incidents are referred to the ministry. When they are, it investigates immediately. Action includes a range of measures aimed at restoring safe practices and confidence among staff and parents."
Parents were divided over the need to tighten up the complaints process.
Hastings mother Phillipa Lamb told the Herald making the information available publicly could put a stop to rumours that sometimes circulated.
"If you had access to proper information you would know exactly how anything has been dealt with, whether police were involved or whatever. You'd be given peace of mind."
Aucklander Mary Bradley, who has two children in childcare, backed making the information publicly available but said it should only be about serious and substantiated complaints, rather than minor incidents that probably happened in most centres.
"The incident could be blown out of proportion and is not necessarily a reflection on the centre."
Labour Party education spokesman Chris Hipkins said there was "no good reason why there shouldn't be transparency".
Litany of tears
The 247 complaints included:
* Teacher bit a child and twisted her hands and arms.
* Parents not told their child had fallen off a slide and had to wait for medical treatment.
* Student on teaching practice saw staff smacking children and dragging them by their arms.
* Child found wandering on the street while centre was unaware he was missing.
* Dogs roaming in play areas.
* Staff not administering prescribed medication to a child.
* Children left alone in vehicles.
* Staff smoking near youngsters.
* Food withheld from pupils.
* Infants' nappies unchanged.