The Irish Nurses and Midwives Organisation has launched a document called "Ward Watch".
It will illustrate any additional patients on wards above their standard complement.
The move comes after claims from the INMO that care of patients in some Irish hospitals is being compromised because of overcrowding.
The organisation will publish daily figures alongside its "Trolley Watch".
INMO General Secretary Liam Doran said this will capture a better picture of what is happening in hospitals.
According to its figures, 1,347 patients were on beds or trolleys in hospital wards above the stated bed complement in the last four-week period.
The INMO says overcrowding is a daily problem at many hospitals around the country.
The hospitals of concern are: Connolly Hospital Blanchardstown, Tallaght Hospital, Mid-Western Regional Hospital in Limerick, Midland Regional Hospital in Mullingar and Wexford General Hospital.