Dublin's Croke Park stadium will host three RBS Six Nations rugby matches and two Republic of Ireland football internationals in 2008.
Croke Park hosted the Ireland v France Six Nations match
But the GAA, who own the ground, said it might not be available to the two sports in 2009 even if the Lansdowne Road redevelopment was held up.
Croke staged its first rugby game on 11 February when Ireland lost to France.
Steve Staunton's Republic side face Wales and Slovakia there in European qualifying matches on 24 and 28 March.
If football and rugby want to use Croke Park after 2008 another motion would have to be passed by the GAA's ruling Congress.
FAI chief executive John Delaney welcomed the latest decision which was taken on Saturday.
"The GAA have been extremely accommodating in granting permission for the playing of our matches in 2008," he said.
"Our focus now is on the upcoming matches against Wales and Slovakia as we continue the preparations with Peter McKenna and his team who have worked in great partnership with us in the build up to the March games."