The IRB under-19 Rugby World Cup was the premier tournament for Men rugby union players under the age of 19 organised by the sports governing body the International Rugby Board (IRB) annually from 2004 until 2007. Both it and the Under 21 Rugby World Championship were replaced by the IRB Junior World Championship for under-20 players which started in 2008.
* Win on number of tries scored
Twenty-four teams take part in each tournament. They are placed into two divisions (A and B) based on rankings. Each division is split into four pools (labeled A-D) of three according to their past performance. Each team plays three matches against three teams of a specific pool (i.e. pool A plays against pool D and pool B plays against pool C). Four points are awarded for a win, two for a draw, and none for a loss. One bonus point is awarded for scoring 4 tries or more, and one bonus point is awarded for loss by 7 points or less.
After all the pool matches, the teams are ranked by total match points. The top four teams qualify for the semifinals (1st against 4th and 2nd against 3rd). Similarly, other teams enter play-offs for positions 5-8 and 9-12.
The winning semi-finalists meet in the final and the losing semi-finalists play to decide third place. The division A winning team wins the tournament outright and the division B winning team earns the right to move up to division A the following year at the expense of the team which came 12th in division A, which falls to division B.