Ward-Smith, who joined London Wasps in 2009, has failed to recover from the lumbar spinal injury sustained in April, and following medical advice has been forced to hang up his boots.
The 33 year-old, who also played for Plymouth Albion and Bristol in his career in the English game, made 49 appearances for Wasps in his two seasons with the club impressing as a strong ball-carrying number 8 with a tireless work ethic.
Ward-Smith also represented England at A level making his debut for the Saxons in 2006 and a first full cap beckoned against Scotland in February 2007, only for a knee injury to rule him out of contention for competing for a World Cup spot later that year.
He lined out for England in four uncapped games on the 2010 southern hemisphere tour scoring a try in the 28-28 draw with the Australia Barbarians in Perth.
The 6ft 4in Ward-Smith appeared throughout his career predominantly as a number 8 but was also comfortable and equally effectively at lock and blindside flanker at the highest level.
Ward-Smith said: “Having to give up the game you love and your career at the same time is beyond devastating. It hasn’t really sunk in yet and the emotion is still quite raw. With the injury I have I don’t have any choice but to stop playing which for me is bitterly disappointing. I want to thank everyone who has had an input in my career at any point, all of my coaches and the players I have played with, the supporters who have cheered me on and especially my wife Jamie who has been hugely supportive throughout a tough few months.”
London Wasps Chief Executive Chris Thomas said: “Everyone at the club is desperately disappointed for Dan, who has been a superb professional and a great guy to have around. He had a hugely impressive first season for us with 29 appearances and four tries and in his time with Wasps he quickly became renowned for his professional attitude on and off the pitch. Dan was one of the hardest trainers the club has ever had and we wish him all the very best in the future and thank him for the effort he has made in the black and gold shirt.”
Ward-Smith is planning on moving back to Bristol where he will pursue qualifications in coaching with the ultimate aim of moving into a strength and conditioning role.
Ward-Smith added: “I know I will miss the training element of rugby almost as much as I will miss playing so I hope to gain the necessary qualifications that will allow me to work in a rugby environment in the future.”
Ward-Smith is planning to return to Adams Park for a home game early in the season where there will be an opportunity for the club and supporters to thank him for his service.