A staggering seven in 10 Irish adults do not wash their hands long enough to remove infection-causing germs.
A national survey has also found that 61pc do not wash their hands after sneezing, 56pc do not wash them after blowing their nose and 65pc do not wash them after coughing.
Today is Global Handwashing Day and the study was carried out by Bon Secours Health System.
Proper handwashing takes as long as singing Happy Birthday twice, according to World Health Organisation guidelines.
It has been shown to reduce the spread of diarrhoea by 31pc and reduce coughs and colds in the general population by 21pc.
The survey found that 18pc of all adults do not wash their hands before handling food and 4pc admitted to not washing their hands after using the toilet.
Women are more likely to wash their hands than men with women typically washing seven or more times a day compared to five times by men, according to the findings.
Almost two thirds of women said they believed that handwashing was extremely important, but only 47pc of men shared that view.
By contrast, 94pc rated washing their hands when visiting a hospital as being "extremely important" or "very important" but 36pc admitted they did not always wash their hands during such visits.
"Washing your hands with soap is still the most effective way to avoid the transmission of harmful germs and prevent health care associated infections," said Helene McDermott, consultant microbiologist at Bon Secours Dublin.
"Handwashing is the first line of defence to prevent the spread of germs in hospitals," added Mary Dunn, Director of Nursing and Clinical Services at Bon Secours Galway.
"We hope that this research and our awareness campaign will help to remind people of the importance of good hand hygiene, particularly in the context of visiting a hospital," she stressed.