One in four small landlords has indicated they plan to leave the rental market in the next five years.
A survey from the Residential Tenancies Board also found most small landlords don't manage properties full-time.
90% of small landlords also said they had a positive experience with their tenants.
The RTB is due to appear before the Oireachtas Housing Committee today.
The Chairman of the RTB will also tell TDs and senators that complex legislation can give rise to unintentional non-compliance by the public.