NCT centres in Dublin, Limerick and Laois have had the highest pass rates in the country this year.
Deansgrange in the capital tops the list, with a pass rate of 62%.
Nearly 906,000 full NCT tests had been carried out in Ireland this year up to last Saturday.
Over 54% of them passed, and nearly 46% failed. However there are big variations around the country.
After Deansgrange, the second highest pass rate is Abbeyfeale in Co Limerick - at 61% - while Portlaoise has a rate of 60.5%.
The lowest in the country is Derrybeg in Co Donegal, with a rate of less than 39%.
That is slightly better than centres in Clifden in Co Galway and Cavan - both at 42%.
Dave Humphreys is the road test editor with completecar.ie.
"Down the country roads can be in poorer conditions, cars will typically do a lot more milage.
"And they're more susceptible to having defects that will result in an NCT fail.
"So things like tracking being out, uneven wear on the suspension: a lot of these can be the result of the roads that they're travelling on".
Over 55,000 cars that had full NCT tests this year were deemed unfit for use on a public road - meaning it's illegal to drive them.
Full results below:
NCT centres with highest pass rates
- Deansgrange - 62.14%
- Abbeyfeale - 61.34%
- Portlaoise - 60.52%
- Cork-Blarney - 59.99%
- Waterford - 59.88%
NCT centres with lowest pass rates
- Derrybeg - 38.81%
- Clifden - 42.24%
- Cavan - 42.37%
- Castlerea - 44.9%
- Carlow - 45.52%
- Letterkenny - 45.6%
