It's been rolling over since last June.
The Lotto jackpot of just over €19 million will definitely be won tonight.
No winning ticket has claimed the top prize since last June 9th, resulting in 63 roll-over draws.
The failure to produce a winning ticket has resulted in numerous complaints from disgruntled players.
However, the National Lottery has received regulatory approval to hold the “must-win” draw.
If no ticket holder matches the first six numbers in the draw, then it will revert to the next highest prize tier – five numbers and the bonus, and so on until a winner is found.
The Irish Examiner explains the odds of getting a win tonight.
They say the odds of matching the first six were in the region of 10.7m to one, but now it is roughly 1.8m to one of matching five numbers plus the bonus.
The main €19m prize has been capped since the beginning of October.
National Lottery spokesperson Fran Whearty, says long-running roll-over draws of this nature will never happen again.
"If we have this unique and unusual situation again; essentially if we get to a cap in the future, it'll be capped for five draws only.
Sales for tickets close online at 7:45pm tonight.
