Over 22,000 cars failed the NCT in the region in the first six months of this year.
The statistics were made available on the official NCT website.
Just over 42,000 tests were carried out in test centres in Carrick-on-Shannon, Cavan, Castlerea, Monaghan and Longford from January to the end of June.
Castlerea had the highest pass rate in the region at 47.84 per cent.
That's followed by Carrick-on-Shannon at 47.33 per cent, while Monaghan recorded 46.26 per cent.
Across the centres, there were 3,443 dangerous failures. Carrick-on-Shannon recorded the highest amount of those, at 769.