Over 10% of Irish adults - roughly 38,000 people - have witnessed adult abuse in the last year, according to new research from Safeguarding Ireland.
The research, which was carried out by Red C, found that 12% of those who witnessed the abuse did nothing at all, while 47% discussed it with the person being abused.
It also showed that 40% of people discussed it with a trusted person.
Just 15% of those surveyed sought professional advice, while 3% reported what they witnessed to an authority, such as the Health Service Executive or An Garda Síochána.
Launching the research, Safeguarding Ireland said it highlighted the need for greater resourcing of safeguarding vulnerable adults, both in terms of effective legislation and a dedicated 24-hour information and support helpline.
Safeguarding Ireland is an umbrella body representing over 30 organisations working to protect vulnerable adults.
Chairperson Patricia Rickard-Clarke said: "The fact that 10% of Irish adults reported having witnessed abuse shows that official HSE figures (in excess of 10,000 alleged cases reported annually) are just the tip of the iceberg".
In 2015, new legislation on Assisted Decision Making was enacted, however it has yet to be implemented.
There is also an Adult Safeguarding Bill in ongoing development in the Oireachtas since 2017.
"The research has told us that stronger laws, which are enforced, is what will drive the public to be more vigilant in tackling adult abuse. We need these pieces of legislation in force with urgency," said Ms Rickard-Clarke.