Ending a 70-day deadlock after an inconclusive election, Enda Kenny was narrowly approved to continue as Taoiseach. He first took office in 2011 following an EU/IMF bailout of the Irish economy.
Kenny won Friday's vote by 59 in favor and 49 against, thanks to the support of independent MPs of the 158-member lower house of Parliament.
Irish public broadcaster RTE said the vote gave him the lowest support in the country's history.
His re-election follows three previous attempts to choose a prime minister after an election on February 26 saw his coalition partner - the left-wing Labour party - suffer devastating losses.
Kenny's own Fine Gael party retained just 50 seats in the election, and he struggled for more than two months to forge a new coalition. After Friday's vote, he becomes the first two-time Fine Gael prime minister.
To achieve the breakthrough, Kenny needed the backing from his party's arch rivals - the opposition Fianna Fail. They agreed to support a compromise program while allowing Kenny to cut separate policy deals with independent lawmakers, three of whom will gain Cabinet posts.
Fianna Fail said it would abstain on contentious votes until the end of 2018, including the next three national budgets.
Will it hold?
"The government I lead will be a very different kind of administration formed in almost unprecedented circumstances," Kenny admitted in parliament after the vote.
Labour leader Joan Burton called it "a deeply flawed arrangement."
Kenny will also name his new Cabinet later Friday. A senior government source said at the weekend that Finance Minister Michael Noonan was likely to be reappointed.
Kenny's previous administration was blamed for the continuation of severe austerity measures following the 2008 financial crisis.
Ireland received more than 67 billion euros ($71 billion) in bailout funds from the EU and International Monetary Fund (IMF) and, in return, agreed to cut public spending and raised taxes.
In the years that followed, the economy has rebounded, growing by almost 7 percent in 2015, and unemployment has fallen.
But many voters complain that despite beingthe eurozone's fastest growing economy, the benefits are not being equally distributed.
mm/sms (AFP, dpa, Reuters)