There has been an 18% increase in complaints of financial abuse against elderly people in the past two years.
The Health Service Executive (HSE) says research suggests immediate family members are most likely to be responsible for this type of abuse.
According to details released under the Freedom of Information (FOI) Act, the HSE got almost 2,300 complaints of elder financial abuse between 2016 and 2018.
The number of complaints rose each year: from 688 in 2016, 790 in 2017, to 810 last year.
The amount of cases found to have a 'reasonable grounds' rose from 37% in 2016 to 51% the following year.
The regions of Ireland with the most complaints were the Midlands, the Wicklow/Dublin southeast area and the Cork/Kerry region.
Paddy Connolly is the chief executive of Age Action.
He says his organisation hears of financial abuse in both residential settings and in people's homes.
"I think there's an issue around education that family members may not be fully aware of taking precaution that their parent or an older relative has a say on where their money is going.
"That if they're taking money for shopping or small things, they may not realise - or it may not sink into them - that that may be financial abuse.
"And then of course we have actual outright exploitation of people and financial abuse".
The HSE says it is committed to safeguarding people who may be vulnerable and at risk of financial abuse.
Reporting by Eoghan Murphy