After he played eight seasons in the Belgian First Division (two with Sint-Truiden, two with Royal Antwerp and four with Standard Liège), Riedl enjoyed a brief spell at FC Metz in France.

He came back to Austria after a single season there, to play for Grazer AK, and then at Wiener Sportclub and VfB Admira Wacker Mödling.

[citation needed] Riedl was capped four times for the Austria national football team, making his debut in April 1975 against Hungary.

[citation needed] As a manager, Riedl coached Olympique Khouribga (Morocco, 1993–94), Al-Zamalek (Egypt, 1994–95), Al Salmiya (Kuwait, 2001–03), and many national teams, including Austria (1990–92), Liechtenstein (1997–98), Palestine (2004–05), Vietnam (1998–2001, 2003–04, 2005–07), and Laos (2009–10).

Then suddenly, on 13 July 2011, he lost his job because of a "contract dispute",[8] after a highly publicized political power struggle within the Football Association of Indonesia (PSSI), and was replaced by Wim Rijsbergen.