Two in every five healthcare workers who raised concerns about wrongdoing were penalised after doing so.
It's even higher than the level of "whistleblower retaliation" seen in policing over the last three years at 38 per cent.
The figure's revealed in a report by Transparency International -- based on data from 566 calls to its whistleblower helpline since 2017.
Its chief executive John Devitt says the sort of corrupt activities that happen in Ireland can only be revealed by insiders who speak up.
"It's extremely difficult to investigate them and the best way to prevent this type of corruption is to prevent them before they actually happen,
"Removing both the incentives and the opportunities for corruption and malpractice, promoting greater access to public information by opening up public contracting more, and again protecting whistleblowers, people within organisations, people who are best placed to expose malpractice."
