The Irish Nurses and Midwives Organisation has become the latest union to accept the Lansdowne Road Agreement for phased restoration of pay cuts.
The vote was 71% in favour with 29% against.
The INMO said that despite the acceptance, it was the union's view that the level of pay restoration proposed - which would average 4.5% over two years - was "very minimal" when compared with the "draconian" cuts imposed unilaterally over the past six years.
It called on Minister for Health Leo Varadkar to recruit 4,000 additional nurses and midwives as soon as possible, following the six year recruitment ban.
INMO General Secretary, Liam Doran said morale in the health service remained very low and members had not yet felt the benefits of any economic recovery.
He said the acceptance of the agreement meant the Government would have certainty regarding pay.
He also called on the Government to introduce "dynamic incentives" to attract recently emigrated nurses back to Ireland.
While some unions have not yet issued the result of their ballots, the deal cannot now be defeated as the four largest unions - SIPTU, IMPACT, the Irish National Teachers Organisation and the INMO - have voted in favour and the overall Congress decision is decided by an aggregate ballot.
The Irish Medical Organisation and the Association of Higher Civil and Public Servants have voted against the deal, and both the ASTI and TUI teachers' unions have recommended a no vote.
