Parks, who joined the region two years ago from French outfit Perpignan, has also played for Newport, Pontypridd, The Celtic Warriors and Leeds Carniege.
His international career saw him pick up four international caps for Wales, as well as representing Wales in the 2001 sevens World Cup in Argentina. He has also played for the Barbarians
Despite battling against an injury to his knee last season and this season's shoulder injury, Parks has been a key player for the Dragons since his arrival to Rodney Parade, notching up 29 appearances in two seasons.
"It's very frustrating as I returned home from Perpignan in order to add to my Welsh caps, an ambition I had never given up on," he said. "I had almost agreed terms to see me stay in Wales at the Dragons as well.
During his career, Richard has won the Principality Cup with Pontypridd and the Powergen Cup with Leeds.
"Obviously I'm bitterly disappointed to finish my career in this way, but I am truly grateful for the career that I have had. I've been privileged to play alongside and against some of the best players in the world and I have a lot of great memories and have made some great friends.
"I have been very fortunate to have been able to experience life in several different clubs and countries. I enjoyed a fantastic spell in Leeds - winning the Powergen Cup and got to experience life in the south of France with Perpignan. My fondest memories will be of my time at Sardis Road with Pontypridd with whom I won my Welsh caps and The Principality Cup.
"Apart from having my 'Grogg' made, winning the Principality Cup with Pontypridd, playing in the sevens World Cup with Wales in Argentina and going unbeaten for the last 8 games during my first season with Leeds to avoid relegation and win the Powergen Cup rank as some of the high points of my career.
"As I started my professional career with Newport, it seems ironic that things have come to an end back at Rodney Parade. I would like to thank the Dragons for all of their support over the last two years; players, coaches and staff alike. I'm also very grateful to my parents for their support.
"We have a great bunch of players at Rodney Parade and it's been a real pleasure to play alongside them. Although the other regions might get more of the spotlight, there are a many young players here who have big careers ahead of them. I believe that the region as a whole has a huge amount of potential.
I would like to thank the Dragons fans who have been outstanding and given me a lot of support over the last two seasons."
Dragons Chief Executive Gethin Jenkins said "Richard has had a great presence at the Dragons both on and off the field. He has been a valuable member of our side and we wish him all the best in the future."
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