Complaints to the Ombudsman, Emily O'Reilly, increased by 9 per cent in 2005, according to her office's annual report.
The Ombudsman's office also dealt with 9,704 queries from the public last year and between valid and invalid complaints and queries, almost 13,000 people contacted the office last year.
The annual report showed that 35 per cent of complainants were better off as a result of having contacted the Ombudsman.
Ombudsman, Emily O'Reilly, gives an example of the type of complaint her office gets.
Of the valid complaints received, 42.9 per cent related to civil service departments and offices, 33.3 per cent involved local authorities, 19.9 per cent related to the Health Service Executive, and 3.8 per cent to An Post.
Ms O'Reilly gave an example of an ongoing case of how her office assists complainants.
"Arising from a particular complaint, I have found that an aspect of the 2005 National Guidelines on Long Stay Charges is inconsistent with the parent legislation.
"The National Guidelines provide that in respect of married couples, the income of a spouse is taken into account in determining the weekly charge for in-patient services, whereas the relevant legislation and regulations provide for the imposition of charges only on persons to whom the in-patient services are provided.
"My complainant's income and that of her husband was assessed and he was being charged €120 per week for in-patient services as a public patient which is €23.90 per week in excess of his weekly Social Welfare pension.
"The Department of Health and Children has agreed with my conclusions on this issue and the Department intends to issue revised regulations in due course," Ms O'Reilly concluded.
The Ombudsman investigates complaints from members of the public who feel they have been unfairly treated by certain public bodies.
Her office is impartial and independent of Government. If she finds a complaint justified she may recommend appropriate redress.
The Ombudsman has extensive powers in law and can demand any information, document or file from a body complained of and can require any official to give information about a complaint.