Up to 70 nurses and midwives are on the picket line outside Wexford General Hospital in the first of six planned 24 hour stoppages over pay and recruitment.
37 thousand members of the INMO nationwide are taking part.
The HSE says it won’t be a “normal day” with all non emergency appointments cancelled.
People are also being advised to only attend the emergency department if it’s essential.
You can hear from staff at Wexford General Hospital on South East Radio throughout the day.