Some creches are not being investigated regularly by the HSE, with a number escaping inspection for up to seven years, according to a report.
The Irish Independent has carried out an investigation into the number of complaints to the HSE about childcare facilities.
It found that at least 280 serious complaints were referred to HSE staff by parents last year.
"Complaints varied from children being allowed to go thirsty, to a child falling down 12 steps of a staircase and nobody seeking medical attention, to a lack of vetting of carers" said Eilísh Oregano, health correspondent with the Independent.
"Then there was a recurring problem with under-staffing, where you might have just perhaps maybe two people looking after 20 children in some cases," she added.