Almost 90% of landlords whose properties were inspected by Dublin City Council have been told to get their houses in order.
The details have been released as part of a clamp-down on sub-standard accommodation.
5,228 were issued between 2012 and August of this year. Local Councillor Nial Ring said the idea is to crack down on "slum landlords".
"At least people who are paying - in some cases- exorbitant rents for bedsits on the North Circular Road, for example, paying maybe €200 a week - at least they're getting a basic standard and decent accommodation now," he said.