Mullingar Regional Hospital was among five worst affected.
Nine times more people were on trolleys in Irish hospitals last month than during April.
According to the Irish Nurses' and Midwives' Organisation, the number rose from 497 in April to 4,499 in October.
Mullingar Regional Hospital was among the five worst affected facilities, with 287 people waiting on a trolley last month - while the highest figure was recorded at University Hospital Limerick, at 1,064.
The INMO says the rising numbers are very concerning, as the winter season begins.
NASA Artemis II Mission Begins Journey Back To Earth
Westmeath Boy To Be Laid To Rest After Devastating Road Accident
Laois Man To Hold Charity Raffle And Open Day This Weekend
Westmeath Cycleway Bridge To Be Named After Late Mary O'Rourke
Former Oireachtas PAC Chair Urges Direct Answers From State Bodies
Westmeath Family Appear In Court Over Violent Row
Revenue Seize Contraband Worth Over €352K
Farmers Vow To Continue Fuel Protest
Three Midlands Garda Stations Left Without Dedicated Officers
Midlands Fire Stations To Benefit From Fire Services Capital Programme
Midlands Motorists Clocked Speeding Over Bank Holiday Weekend
Gardaí Seek Witnesses Following Westmeath Burglary
Teacher Pay, AI And Staffing Crisis To Dominate Union Conferences
Electric Picnic Organiser Sees UK Festival Cancelled After Kanye West Booking
Missing Offaly Man Found Safe And Well
Man Dies Following Midlands Crash
Storm Dave Leaves Hundreds Of Midlands Homes Without Power
Laois Dairy Farm Submits Planning Application To Retain Onside Accommodation
Westmeath’s Musical Link To Sinead O’Connor Highlighted By Wax Museum Update
Moneygall To Feature On New US Presidents Trail Celebrating Irish Roots