Almost 200 childcare providers in England have gone out of business after being judged inadequate in Ofsted inspections, the watchdog has revealed.
Most provision is at least satisfactory
It added that up to 10,000 children had been spared inadequate childcare thanks to new inspections.
Most of the 1,100 providers that had been judged to be inadequate between April 2005 and June 2006 had improved by the time they were inspected again.
But 180 resigned their registrations and 11 had them cancelled.
Anyone working as a childminder or providing day care for children under the age of eight has to be registered.
One example given in the report is of an unnamed nursery where, Ofsted said, children's hygiene was "poorly promoted" - with "inappropriate" access to pets and no emphasis on hand washing after using the toilets and before eating.
Their safety was compromised by poor supervision, particularly when they were playing outdoors.
"Children had to wait for too long between activities, behaviour was poor and they were not encouraged to show respect for each other," Ofsted said.
"The nursery had a poor partnership with parents, including a lack of necessary records and consents to meet children's needs."
Following the inspectors' intervention the provider resigned.
Ofsted's report said there had been a loss of childcare places as a result of its enforcement actions, but they had been poor quality ones.
"Ofsted's actions ensured that children in these settings were removed from the risk of harm," it said.
Another 61 providers were put on immediate notice to improve.
"The remaining providers judged to be inadequate will be re-inspected - on schedule - by the end of June 2007."
Chief inspector Maurice Smith said: "Ofsted's vigilance has 'made a difference' for 10,000 children.
"They now have a better quality of care because we picked up on providers' evident weaknesses and insisted that improvements were made quickly."
The level of improved childcare following re-inspection was higher among childminders than day-care providers.
The National Day Nurseries Association said Ofsted's latest report was welcome but further work was needed to promote the high-quality care that the vast majority of day nurseries provided.
It said people should remember that 97% of providers gave a satisfactory, good or outstanding level of care for children.
A spokesman for the Department for Education and Skills said: "This report by Ofsted shows that the vast majority of parents can be very confident that their children are kept safe and healthy in their chosen childcare setting.
"The significant investment that we have put into childcare and early years services is paying off by giving children access to high quality care.
"Where childcare settings are failing to meet the national standards, Ofsted works with the provider to improve the quality of care or takes the necessary steps to cancel registration."
Making a difference: how Ofsted inspections improved inadequate care for children is published by the Office for Standards in Education.