I liga Rugby is the second tier league for rugby union in Poland.

Originally there were two divisions, consisting of 8 teams in the Rugby Ekstraliga and 6 in I liga, however as the sport is growing in popularity and more and more teams are being registered, third division has now been created, the II liga Rugby.

For victory, a team gets four points, two points for a tie and zero for a loss.

In the event of a forfeit, the team unable to play will be docked 1 point and their opponent will be awarded a score of 25-0 and 5 points.

The champions are promoted to the Rugby Ekstraliga, and the last placed team are relegated to the II liga Rugby.