In 2004 Jaidee became the first Thai to win a tournament on the European Tour with his win at the Carlsberg Malaysian Open. In 2005 he successfully defended his Malaysian Open title. After winning the 2006 Volvo Masters of Asia Thongchai reached 75th in the Official World Golf Rankings. In 2009 Jaidee recorded his best European Order of Merit ranking of 19th.
Jaidee won for the fifth time on the European Tour in June 2012 at the ISPS Handa Wales Open. He shot a final round one over 72, but won by a single stroke from four other players.
Jaidee was the first man to win US$2 and US$3 million on the Asian Tour.