Thieves have stolen the contents of a display cabinet from Liverpool Football Club's museum.
The pennants were presented to Liverpool's Steven Gerrard
A club spokesman said eight pennants presented by opposing teams before each round of the 2004-2005 Champions League competition were taken from the museum.
The haul included the pennant from the final against AC Milan in Istanbul in May which Liverpool won.
It is thought the thieves took the pennants on 27 December. The club is offering a reward for their return.
A spokesman for the Premiership club said: "This selfish act has robbed us all of the pennants handed to Steven Gerrard (club captain) before each round of the 2004-05 Champions League, including the final.
"The eight pennants are clearly identifiable, with the date and game embroidered on all but two of them, and a unique museum number starting with "LFC" on the reverse in black, indelible ink.
The club said a reward would be offered to anyone who could secure the return of the pennants which the spokesman described as "vital pieces of our history".