Women in Ireland receive 27% less than men in pension entitlements.
New figures from Eurostat show that the gap has narrowed from a differential of 35% in 2010.
The gap exists because many women who leave the paid workforce to raise children make fewer PRSI payments.
Gerry Kiely of the European Commission office in Dublin says more needs to be done to rectify the situation.
"The Irish situation is better than the average in Europe and the trend is in a positive direction," said Mr Kiely.
"Nevertheless, a gap of 27% between a woman and a man's pension is unacceptable.
"It needs to be rectified as soon as possible."