The annual report of the independent body reveals that the number of appeals increased by 27% over the previous year and was the highest since 1993.
The Social Welfare Appeals Office deals with challenges to decisions about entitlement to welfare benefits, including emergency payments of Supplementary Welfare Allowance.
It also handles questions about the insurability of employment.
The number of appeals jumped from just over 14,000 in 2007 to almost 18,000 last year.
Just short of half the appeals succeeded, four out of ten were disallowed and 13% were withdrawn.
Announcing the report's findings, Minister for Social and Family Affairs Mary Hanafin said the number of appeals largely reflected the increasing number of claimants.
She added that almost 2.5m claims were cleared by the department and it was understandable that not everybody agreed with those decisions.
The Department says the appeals system is judicial in nature leaving very limited scope for fast-tracking cases.
