Having briefly lost the record, the Blues then regained it when 15,327 supporters cheered on the team in a thrilling match against Leinster at the Millennium Stadium. Over 118,000 supporters passed through the turnstiles and this season's attendances have increased by over 20% on the 2004-2005 season.
"It's a hugely encouraging achievement to break the attendance record twice in one season. The support for the team has been tremendous with the culmination of this being the impressive turnout we had for the match against Leinster in the Millennium Stadium," said Blues Chief Executive Robert Norster.
"The feedback we have received from everyone who was involved in that match has been great, from the supporters, sponsors, players and coaches, everyone got behind the cause and it was a very successful day.
"It's good to hear such positive feedback and reassuring to know that following our staff's significant efforts everything ran smoothly on the day. We are certainly not ruling out the possibility of playing another game at the National Stadium in the future."