Two prosecutions emerged from a total of 58 complaints and inspections received about pre-schools, play groups, nurseries, creches and daycare services last year.
An analysis of 500 randomly selected inspection reports of early childhood services found that 38pc had not complied with the law to have all workers vetted.
The 2015 annual report of Tusla - the Child and Family Agency - also highlighted problems with other issues, including child safety, as 49pc were not compliant in dealing with hazards such as cord blinds, allowing children access to first aid boxes and electric kettles.
Other hazards highlighted included unrestricted access to a hotel car park, toys which could cause injury with sharp, exposed edges and rodent droppings in a hot-water unit.
Two large barking dogs were found in one outdoor play area. Some showed no evidence of insurance cover.
Tusla found one blind cord was not secured to the wall and posed a strangulation risk. The report said 2,302 early years services were inspected last year by Tusla, a 74pc increase on 2014.
Some 58 complaints received about early years services were investigated and two prosecutions were taken. The outcome of the prosecutions is unknown.
There was also a significant problem with lack of references for staff and the absence of a person in charge was discovered in nine facilities. Other instances of risk involved a child sleeping in a swing, staff observed not washing their hands after changing nappies, an inadequate number of cots and the routine checking of sleeping children not recorded.
In other cases, inspectors found adults who supervised children at lunch time had little interaction with them.
The highest category of complaints related to governance and the running of the facilities.
This was followed by health, welfare and development of the child. Meanwhile, a quarter of cases related to safety.
Parents made more than half of the complaints but they also came from grandparents, neighbours, care workers and students. One-third of complaints were upheld.
"While we identified a lot of good practice and there were high levels of overall compliance with the regulations, it is clear that there are still some areas that require further attention and improvement on the part of early years services," Brian Lee, Tusla Director of Quality Assurance said.
Asked about garda vetting, a spokesman for the Department of Justice said 80pc overall vetting applications are now being processed by the National Vetting Bureau in five working days. An e-vetting system which facilitates the online processing of applications from registered organisations is now in place.