A total of 31 teams participated in the competition. Italy were represented by two clubs, with Milan qualifying as title holders and Inter Milan as Italian champions.
CSKA Red Flag wasn't participating after spell of seven editions, with only ever-present Real Madrid having more appearances in the competition.
Spartak Plovdiv,
Anorthosis Famagusta,
Motor Jena,
Everton,
AEK Athens,
Ferencváros, Inter Milan,
Valletta,
Distillery,
Lyn,
Dundalk and
Zürich made their debut in the competition.
PSV Eindhoven returned to the tournament for the first time since
inaugural edition, while
Borussia Dortmund and
Jeunesse Esch returned to the competition after six and three years, respectively. All participants were their respective associations champions, except for Milan and Lyn. The latter was leading
1. divisjon at the summer break on 1 July 1963, after 9 of 18 matches had been played, but finished second when the league ended in October. ==Preliminary round==