Smith began his career as an apprentice footballer with his home town club, Middlesbrough, but a broken leg at just 17 years old meant that he had to retire. Determined to stay in the game, he trained as a physiotherapist, earning his first appointment at Rotherham United in 1972. After five years at Rotherham he moved on to Blackpool, where he stayed for six years. In 1983 he was appointed physiotherapist at Sheffield Wednesday, remaining with the club for eleven years, from the Football League Second Division to the Premier League and European competition. He first worked with the England national football team in 1986, and in 1994 Terry Venables appointed him as England's physiotherapist on a full-time basis, a post which he held for eight years, working under seven different managers. He also worked for Blackburn Rovers on a part-time basis. He renewed his association with Sheffield Wednesday in 2009 in the role of part-time consultant physiotherapist.
Smith's son Paul, also a chartered physiotherapist, joined Sheffield Wednesday in April 2009.