Dublin has the lowest number of inspectors of creches in the country - with some facilities not inspected for up to six years.
Pre-schools in the capital are operating without adequate monitoring of safety and quality standards due to a shortage of inspectors.
The ratio of inspectors to children in Dublin north east is one per 21,052, according to figures obtained by Independent TD Roisin Shortall.
"Dublin north east, comprising north Dublin and the north east of the country, has the lowest number of inspectors - only five in total. This is despite having one of the highest child populations," she said.
"By comparison, the western area has a ratio of one per 6,893."
The figures from Tusla, the child and family agency, showed there were 42 pre-school inspectors last year and 2,432 inspections, although there are 4,600 facilities.
There are 19 inspectors in the west but just five in the HSE Dublin North-East area covering Dublin north west, Dublin north, Dublin north central, Meath and Cavan-Monaghan.
There are eight inspectors to cover Kildare, west Wicklow, Dublin west, south west, and south east, Dun Laoghaire and parts of the Midlands.
Figures show nine inspectors to cover Kerry, Cork, Wexford, Waterford and south Tipperary.
Ms Shorthall said she was concerned in the wake of revelations about poor standards in some pre-schools in an undercover television expose more than a year ago.
Commenting on the figures Teresa Heeney, chief executive of Early Childhood Ireland, said she knows of pre-schools which have not been visited for six years.
"We need regular and consistent inspections across the country and this cannot be done when the numbers of inspectors are not enough," she stressed.
"We also need inspectors with specialised early childhood training rather than leaving it to public health nurses."
Gordon Jeyes, chief executive of Tusla, said vacancies have been filled and a full complement of 42 inspectors will be enhanced with another six posts.
"Currently, there are approximately 4,600 early years service providers and therefore the target ratio will be one inspector to every 100 services," he said.
The workforce will operate nationally under the scrutiny of four senior inspectors, whose posts are advertised, and a national manager, whose job will be advertised shortly. They will in turn report to a Director of Quality Assurance.
"All services will be inspected every three years," he said.