135,000 people are waiting for diagnostic scans according to Fianna Fáil.
The party says more than 17,000 people are waiting over a year for essential scans.
The figures only refer to a limited number of procedures, CTs, MRIs and Ultrasounds.
"The data itself is a cause for significant concern," said Health Spokesperson, Stephen Donnelly. "Some 44,123 people are currently waiting for an MRI scan – almost 9,450 of who have been waiting over one year. 5,422 are waiting more than a year-and-a-half.
“An Ultrasound is proven to be an essential diagnostic tool in medicine, yet 59,404 people are waiting for this important procedure in Ireland. 6,018 are waiting more than a year while 3,535 have been waiting more than 18 months.
“CT scans provide medical information that other imaging techniques cannot as accurately identify and on that basis both practitioners and patients rely on access to the scan. That’s why it’s so concerning that 31,567 people are waiting without even knowing when they might receive an appointment."
Mr Donnelly said it also raises the question of what treatment patients could be missing out on.
"The question you have to ask is what level of intervention, what level of medical care, what level of treatment are patients missing out on because their doctors and their nurses don't even know what's wrong with them yet."