Minister for Social Protection Leo Varadkar has apologised to the 1,300 woman waiting over four weeks for their maternity benefit payment.
He urged women who would be applying for the payment to do so online as it would be processed much more quickly.
His department has said that the implementation of a new system, and the training of new staff, had resulted in the delays.
There were 2,850 claims for maternity benefit waiting to be processed, Mr Varadkar said.
He told RTÉ's Morning Ireland the backlog had built up over a number of weeks, and would continue for another "couple of weeks".
An exceptional need payment can be paid, in certain cases, by local social welfare offices, he added.
“Everyone will get their money. They will be paid the arrears.”
The department said the delays were temporary but warned some women would not receive any payments until four weeks after their maternity leave began.
Maternity benefit of €235 a week is paid once a woman has accrued enough PRSI credits.
Mr Varadkar said that extra staff were being brought in and staff were working overtime in an effort to speed up the process.