The 1999–2000 French Rugby Union Championship was played by 24 teams divided in the preliminary phase in two pool of 12.

The team classified from 3rd to 6th of each pool were admitted to a Barrage round.

Ath the end of the season four team were relegated to lower division: Montauban, Toulon, Racing Paris, Nîmes.

Because of a default of 10 million French francs, the Ligue Nationale de Rugby relegated the June 24, 2000 the RC Toulon in the second division.

A Barrage match was arranged between Aurillac and Racing Paris.