A glitch could have seen people who've had x-rays or ultrasounds given the wrong results.
The problem relates to a keyboard symbol used in medical reports.
The Irish Times says the problem is linked to the 'less than' symbol, which makes symptoms appear worse than they are.
For example, where someone had a narrowing of the arteries of '<50%', this would be wrongly recorded as '50%'.
The paper says the problem is with images of patients' tests held at the HSE's National Integrated Medical Imaging System (NIMIS).
But it's claims no one is likely to have suffered serious clinical harm.
The system has been changed to replace the symbol with the actual words 'less than'.