Speaking at the Arms Park, Cuthbert, said,
"I had a lot of decisions to make but I'm glad I've got it sorted and this is the place I want to be to take my rugby career forward. I'm glad it's all sorted now.
"I did have some good offers from other clubs but I wanted to stay with the Blues.
"I've certainly seen the progress on the pitch, although we may not be getting the results right now, we are just losing by narrow margins and you can tell it's coming.
"Hopefully we will get some quality players in next season and those close losses will turn into wins for us."
Talking of his future at the Blues, Cuthbert added,
"Obviously the likes of Rhys Patchell has just come in and stepped up to Heineken Cup level and that's what we want at the Blues. Josh Navidi has come on loads also and playing really well. It's good to see Tom Williams and Owen Williams coming through.
"A year or so on, with a bit more experience under their belts, they will only be better.
"I'm happy in Cardiff and with the Blues. I get on really well with Phil and the coaching staff and enjoy playing with the boys.
"I'm just looking forward to the rest of the season starting with our derby matches over Christmas against the Scarlets and Dragons.
"It's great playing at the Arms Park. There's a great atmosphere with the crowd on top of you and it always lifts you to play in front of a packed house.
Speaking of Alex's decision to stay Cardiff Blues Director of Rugby, Phil Davies, added,
"I am delighted that Alex Cuthbert has signed a contact with the Blues, keeping him in Wales for the next three years.
"Alex is twenty-two, he has a fantastic future ahead of him, not just at the Blues but in the game in general.
"He is a vital part of our squad and I'm sure that our supporters are also delighted as are the players in the squad.
"Alex is s a great try scorer but he is still young and developing all the time.
"His work rate is phenomenal and his defence and reading of the game is improving considerably. Hopefully he will get better and better over the next three years."
Cardiff Blues play the Scarlets on Friday 21 December 7.05pm and the Dragons on Boxing Day at 2.05pm. Tickets are available online at www.cardiffblus.com/tickets or by calling 029 2030 2030