Xavier Rush arrived in Cardiff in 2005 from Auckland Blues, where he won the Super 12. Last year he was nominated captain of the team and has made a huge impact as a big ball carrying No.8.
David Young, Cardiff's Director of Rugby, was delighted with their decision: "I think both players have made big impacts since they've arrived and they've been important players both on and off the field," he said.
"They make a big contribution to helping us move forward and it's pleasing to retain two quality players."
Cardiff, who top Pool 3, will play Bristol for their final pool match. The Blues need a victory over the English side if they want to qualify for the quarter-finals for the first time since regionalisation in Wales.
Only one team has beaten Bristol this season at the Memorial Ground, it is sure to be a close encounter with both sides fighting for their lives.