The country's polling stations closed at 22:00 GMT on Saturday.
Ruling Fine Gael party, led by Prime Minister Leo Varadkar, has won 22.4 percent of the vote, while opposition Sinn Fein and Fianna Fail parties have got 22.3 percent and 22.2 percent respectively.
The preliminary results are expected to be announced on Sunday. The new lower house is scheduled to meet for the first time on 20 February.
On 14 January, Ireland's Michael Higgins dissolved the lower house at the request of Prime Minister Leo Varadkar.
Since 2016, Ireland has been governed by a cabinet formed by Fine Gael with the support of independent lawmakers.
