The NCT test centre in Ballinasloe has one of the highest pass rates in the country while Castlerea has recorded one of the lowest.
New figures have revealed that a total of 14 testing centres including, 2 in the Shannonside Region, had pass rates below 50 percent.
The Ballinasloe NCT Centre has a pass rate of 59.8 percent, with Longford close behind at 55.4 percent.
Athlone is next on the local list, with 54.2 percent of all vehicles getting the greenlight from the test.
Meanwhile, according to figures from the Independent.ie, Carrick on Shannon and Castlerea both had some of the worse rates nationwide, with less than half the cars passing inspection in Leitrim and just 45 percent of vehicles passing in Castlerea.
The center in Derrybeg in Donegal has the lowest pass rate, while Deansgrange in South Dublin had the highest.
Shane O’Donoghue, Motoring Journalist with Complete car.ie said its possible that tougher road conditions and greater mileage travelled could have an impact on the result in Donegal.
"We don't have the data to support it but the thing is in those areas the roads are a little bit worse, people are driving longer, and they're driving more on rural roads then they would in Deansgrange in the middle of Dublin so the cars are subjected to harsher conditions for more of the time".