Playing for the Dolphins his first twelve seasons, he was selected to the Pro Bowl eight times and recorded over 1,700 tackles. The last two years of his career, Thomas spent with the Dallas Cowboys and the Kansas City Chiefs, respectively. He officially retired from the sport on May 18, 2010, when Zach Thomas signed a one-day ceremonial contract, worth $1, in order to retire as a member of the Miami Dolphins. On the field, he enjoyed a successful career decorated with numerous accolades, while off the field, he auspiciously played the role of a husband and father of two.