Anyone who is injured or feeling unwell this long weekend is being urged to consider a pharmacy, out of hours GP or injury clinic as their first port-of-call.
The HSE said hospitals are already "extremely busy", and it wants people to stay away unless absolutely necessary.
However, the HSE is stressing that anyone who presents to an emergency department over Easter will be seen and treated, with those most ill and urgent cases being prioritised for care.
Sinn Féin health spokesperson David Cullinane said more money for healthcare, and an end to the HSE recruitment freeze, are urgently needed.
Mr Cullinane told Newstalk: "The funding is not there. The Minister for Health of course has to take responsibility, so to does the entire Cabinet.
"If Simon Harris really wants a change of direction in relation to health services, and really wants a spec change, well then the first course of action he should take is to reverse that disastrous decision that was put in place by him and his Cabinet colleagues, to put in place this recruitment embargo."
