It has led to calls for the department to regularly publish salaries
Female staff in the Department of the Taoiseach earn an average of €12,764 a year less than their male counterparts.
Documents released under the Freedom of Information Act show a large pay gap within the department.
It has led to calls for Enda Kenny's department to regularly publish what it pays male and female employees.
There are almost twice the number of female employees in Mr Kenny’s department than male - 123 women to 71 men.
On average, male employees take home €61,472 - while female staff are earning €48,708.
The Department of the Taoiseach that say all staff are paid according to standard civil servant pay scales and that this is not affected by their gender.
This takes into account the rank and seniority of the different officers.
The department also points out that 77% of principal officers in the department are female.
This suggests that while there are female employees relatively high up on the pay scale, most of them are lower down and the very top and high paying positions are men who are earning more.
Orla O'Connor of the Women’s Council of Ireland says that is something they quite often see.
She also says she does not believe companies are unaware of the earnings.
As part of the Programme for Government, it said: "We will strengthen the role of the Low Pay Commission in relation to the gender pay gap and in-work poverty. We will strengthen regulation on precarious work."
They also promised an updated National Womens' Strategy. This was due this month, but will be delayed until next year.
As of November 23rd consultation work on the document had yet to start.
The issue was put to Junior Minister Helen McEntee.
"That's something I would support, I'm 100% percent behind equal pay for men and women - so I would be interested to follow up on that most certainly".