A total of 86 failings by six nurses, relating to vulnerable people in their care in Caerphilly county, have been found proven by a disciplinary panel.
They relate to nine residents at the Brithdir Care Home, near Bargoed, between 2004 and 2006.
They include failing to prevent pressure sores and delays in seeking advice about an infected feeding tube.
A Nursing and Midwifery Council (NMC) panel is yet to decide whether the nurses will face sanctions.
Rachel Tanta, Rachel Pritchard, Tembakazi Moyana, Beverley Mock, Daphne Richards and Susan Greening had been accused of more than 150 failings.
Other failings found proved at a hearing on Friday included failing to keep adequate records, failing to set up care plans and failing to ensure a resident was prescribed antibiotics for pressure sore when a GP said they were necessary.
There was also no record made of a resident vomiting and no contact made with a dietician in relation to it, the panel found.
A total of 18 failings were proved against Ms Tanta, a registered nurse. Five were proved against Ms Mock.
Twelve were proved against Ms Pritchard in her roles as clinical nurse manager and later nurse director.
Twenty eight were proved against mental health nurse, Miss Moyana.
Fourteen were found proved against against Ms Richards in her roles as registered nurse, acting manager and later bank nurse.
There were also nine proved against Ms Greening, who was a registered nurse and later care home manager.
A further hearing, on a date yet to determined, will be required before the disciplinary panel can decide whether the failings in each nurse's case amount to misconduct and whether their individual fitness to practise is impaired.
Any sanctions they face will then be fixed.
Last year, an NMC panel found seven misconduct charges proved against Christine Hayes, the director of nursing at the Caerphilly Local Health Board between 2003 and 2006.
She was found to have kept moving people to the home despite knowing of serious concerns over standards, and was struck off in January, this year.
Concerns were raised about Mrs Hayes' actions during a major investigation by Gwent Police into allegations of neglect in care homes, called Operation Jasmine.
The home - which has 40 residents with dementia, mental infirmity and learning difficulties - is now under new management.