Originally covering clubs in Cardiff and the Vale of Glamorgan unitary authorities, in 2004 the region was expanded to include clubs in south Powys, Merthyr and Rhondda Cynon Taff.

The main professional team competes in the Magners League, Heineken Cup and EDF Energy Cup.

The region is also represented by teams at Under 16’s 18’s and 20 age grade level that encompasses a player development pathway with future players being identified for selection into the Blues Academy in Trefforest. The Blues have been victorious at Under 20 and Under 16s level in this competition. 

The region also runs a Blues Clubs XV made up of amateur players who play in the ASDA Leagues

There are 64 clubs within the region including three clubs in the Principality Premiership and the remainder participating in the Swalec Leagues.

The Blues qualified for the first time in their brief history for the Heineken Cup Quarter Finals in 2007/8, losing out away to eventual runners up and three times European champions Toulouse.

The team has finished second in the Magners League in the last two consecutive seasons, just pipped at the final round of matches by Ospreys in 2006/7 and Leinster in 2007/8.

The Ospreys also proved to be the undoing of the Blues during 2006/7, in the EDF Energy Cup, as the Blues lost 10-27 at the Millennium Stadium. This appearance was the third of four occasions the Blues have played at the national stadium. On the first occasion Cardiff Blues beat Leinster in 2005/6 and set a then Celtic League record attendance.

This was followed by a record crowd of 26,645 (a record for a welsh regional Heineken Cup pool game) when Cardiff Blues narrowly lost to Leicester Tigers in 2006/7. During 2008/9, the Blues went better still on and off the field, at the Millennium Stadium, beating Gloucester in a 7 try thriller, 37-24 in the Heineken Cup pool, and setting another record for the attendance of 27,114.

The Blues recorded a record win of 58-0 against Connacht in September 2008, and a record Heineken Cup win the next month 56-20 away at Calvisano in October 2008.  

The record for points scored in a match was 60-14 against Munster in the Celtic League in April 2004. The highest points scoring match (77 points) is shared by both a 55-22 victory over Edinburgh on 13th May 2004 and a 49-18 defeat at the hands of Munster in October 2005. This is also the heaviest defeat for Cardiff Blues.

The Blues have four players in their squad that have represented the British & Irish Lions, Gethin Jenkins, Tom Shanklin and Martyn Williams, plus once record Wales try scorer and 100 Wales cap man Gareth Thomas, who played for the Lions  before joining the Blues in the summer of 2008.

As well as the four aforementioned players Cardiff Blues also have a number of Wales internationals in the current squad including, Nick Robinson, Jamie Robinson, Scott Morgan, Deiniol Jones, Chris Czekaj, Tom James, Aled Brew, Rhys Williams, Jamie Roberts, Robin Sowden-Taylor, Ceri Sweeney, T Rhys Thomas, Gareth Williams, John Yapp. Leigh Halfpenny and Andy Powell are also in the current Wales squad for the Autumn International Series 2008 and could make their international debuts. 

Cardiff Blues have also had three players that have played for the All Blacks, former captain Xavier Rush, Ben Blair and legend Jonah Lomu (who played for the Blues during 2005/6). Current captain Paul Tito also played for New Zealand Maori and there are also two Tongans Maama Molitika and Fao Filise in the squad. 

Lock Deiniol Jones was the first player to reach 100 appearances for the Blues, picking up his special cap at the end of season dinner in May 2008. Fly Half Nick Robinson is the highest points scorer for the Blues in their history with 641 points (November 2008). Nick also now holds the record for most appearances for the Blues, with 107. Nicky's brother Jamie, tops the leader board for the most number of tries - 25.  

The Cardiff Blues are totally committed to supporting rugby activities throughout the region.  The Future Blues Community Rugby initiative provides hands on coaching to youngsters under the age of 16 as well as delivering support to the teachers, club coaches in terms of a range of activities including rugby development, first aid, refereeing and budget applications.