The Scottish FA Cup was played for the 106th time in 1990/91 . The most important Scottish football cup competition, which was directed by the Scottish Football Association, began on December 8, 1990 and ended with the final on May 18, 1991 in Hampden Park in Glasgow. As the defending champion, FC Aberdeen started the competition, which prevailed against Celtic Glasgow in the previous year's final . The Dons reached the third round in this year's event in which they were defeated against the eventual winner, FC Motherwell . Motherwell FC celebrated their second FA Cup title after 1952 with a 4-3 win after extra time against Dundee United . The two teams were coached by the two brothers Tommy and Jim McLean . Previously, the Motherwell club had reached the finals in 1931 , 1933 , 1939 , 1951 and 1952, of which only the 1952 final was won against FC Dundee . Through the Cup victory, Motherwell could simultaneously for the UEFA Cup Winners' Cup season review 1991/92 qualify.