Kuhn has been described as a clever and skilful midfielder. He spent 16 years with FC Zürich, captaining them to the Swiss Super League six times, as well as the Swiss Cup five times. He also played for Zürich in European Cup semi-finals in 1963 and 1977. He left FCZ for city rivals Grasshopper Club Zürich for a short period towards the end of his career. Internationally he won 63 caps, and as a 22-year-old played one game at the 1966 World Cup, before being sent home in disgrace, and later banned for 12 months from the national team, for breaking a curfew.

After retiring as a player, Kuhn returned to FC Zürich in 1979 to take charge of their youth set-up. He was later caretaker-manager of the club for two short spells between May 1983 and July 1984, as the club searched for a permanent successor to Daniel Jeandupeux. In 1995, he left the club and took a youth-coaching position at the Swiss FA. He led the national under-18 side to an impressive showing at the 1997 European Championships, and later guided the U21s towards qualification for the finals of their respective European Championships for the first time.

Kuhn was promoted to coach of the senior national team in June 2001, replacing the Argentine Enzo Trossero. Kuhn had been approached to become Trossero’s assistant, but turned down the offer. With no real senior coaching experience, his appointment as head coach was first not universally applauded, but he has led the Swiss to Euro 2004 and the second round of the 2006 World Cup. Since Kuhn took part in the 1966 World Cup as a player, Switzerland had qualified for just one World Cup, in 1994, and one Euro finals, in 1996. Kuhn spent seven years as coach of the national team, and utilised many of the youth players he had worked with at youth level, ultimately helped building a successful football generation that would be later inherited by Ottmar Hitzfeld. He is second in all-time matches coached for the Swiss team, behind Karl Rappan.

Kuhn announced in October 2006 that he would terminate his engagement as manager of the Swiss squad after Euro 2008. In the week leading up to the tournament, Kuhn’s preparations were disrupted by an epileptic attack hospitalising his wife.