There are now 65 clubs within the five unitary authorities within the Cardiff Blues region. The WRU formed a new Division 6 in the 2007/08 season that enabled district clubs to become WRU clubs.
The district clubs that became WRU clubs that season were: Clwb Rygbi Cymru Caerdydd RFC, Llanrumney RFC, Llandrindod Wells RFC, Cambrian Welfare RFC, Wattstown RFC, Ynysowen RFC, Caerau Ely RFC, Sully Sports RFC and Glyncoch RFC

Cardiff

Cardiff RFC, Glamorgan Wanderers, UWIC, Rumney, Fairwater, Llanishen, Pentyrch, St Peters, Cardiff HSOB, Taffs Well, Old Illtydians, Llandaff North, Llandaff, Canton, Rhiwbina, St Albans, St Josephs, Cardiff Medicals, Cardiff University

Vale of Glamorgan

Llantwit Major, Barry, Cowbridge, Penarth, Dinas Powys, Old Penarthians

Rhondda Cynon Taf

Pontypridd, Abercynon, Beddau, Llanharan, Ystrad Rhondda, Llantrisant, Llantwit Fardre, Mountain Ash, Rhydyfelin, Treherbert, Ynysybwl, Gilfach Goch, Hirwaun, Tonyrefail, Treorchy, Tylorstown, Abercwmboi, Aberdare, Cilfynydd, Porth Harlequins, Ferndale, Penygraig, Pontyclun, Rhigos

Merthyr Tydfil

Merthyr Tydfil, Bedlinog, Cefn Coed, Dowlais

South Powys

Builth Wells, Brecon, Gwernyfed