What is the highest rugby league scoreline?

The highest NRL score was the Brisbane Broncos and West Tigers

Broncos won 208 - 0 in 1996

Next was Broncos and Knights

Broncos won 154 - 4

Both games were in the same year.

The highest score in a NRL/ARL/NSWRL game was St George (91) defeating Canterbury (6) in 1935. Source- NRL stats.