Three hospitals were not fully compliant with required staffing levels during inspections last year, according to the health watchdog.
Trips to Cork University Maternity Hospital, University Hospital Kerry and Tallaght University Hospital took place between late September and October.
Inspectors found 'gross overcrowding' in Kerry's Emergency Department and a 'significant' shortage of staff in that unit.
Overcrowding was also noted in Tallaght, with HIQA's report concerned the environment didn't give patients the dignity or privacy they deserve.
Both of those visits were un-announced, which means staff and management did not have an opportunity to prepare for it.
A visit that was announced at Cork University Maternity Hospital found it had effective structures in place to make sure high quality, safe and reliable healthcare was delivered.
However, HIQA also noted a shortage in the levels of medical, nursing and midwifery staff - which management was working to address.
The Irish Nurses and Midwives Organisation has called on Government to 'heed the warnings' from these reports.
It says of ten reports from the last eleven months - not a single hospital was fully compliant with safe staffing levels.
