Thousands of gay men are expected to take part in a new online survey on sexual practices.
Researchers behind the HSE questionnaire want to track the latest health trends to help fight the spread of STIs.
According to the health authority, gay men accounted for the highest number of new HIV diagnoses in Ireland over the past two years, at 46 per cent.
The survey goes live online today at misi.ie and it's open to any gay man living in Ireland, over the age of 18.
Doctor Derval Igoe, a specialist in public health medicine with the HSE, said the last study of this kind was carried out five years ago.
"From that, we identified that about two thirds of men had ever tested for HIV. What we're hoping now is that we'll find more men are," she said.
"We also found that people were less likely to test for HIV if they were younger, if they weren't living in urban areas, or if they identified as bisexual."
She said she hoped to see improvements in all those areas.