The 2004–05 European Challenge Cup (known as the Parker Pen Challenge Cup for sponsorship reasons) was the ninth season of the European Challenge Cup, Europe's second-tier club rugby union competition below the Heineken Cup. A total of 28 teams participated, representing seven countries. The competition began with a series of matches on 23 October 2004 and culminated in the final at the Kassam Stadium in Oxford on 21 May 2005. As in the previous two seasons, the competition was organised in a knockout format. Teams played each other on a home and away basis, with the aggregate points winner proceeding to the next round. The final was a single leg. This was the final season with a pure knockout format; in subsequent seasons the competition reverted to a pool stage followed by a knockout. For the third and final time, a third tier tournament was held - the European Shield. This was contested between the first round losers from the European Challenge Cup. As there were only 28 teams involved, the 2 "best" 1st Round losers were reprieved and proceeded to the 2nd Round. The defending champions, England's NEC Harlequins, did not have a chance to defend their crown because they qualified to play in the Heineken Cup. Sale Sharks claimed a comfortable victory over Pau in the final and picked up their second piece of European Club silverware.

Teams

The allocation of teams was as follows:

Matches

All kickoff times are local to the match location.

Round 1

1st leg

2nd leg

Aggregate Results

Round 2

1st leg

2nd leg

Aggregate Results

Quarter-finals

1st leg

2nd leg

Aggregate Results

Semi-finals

1st leg

2nd leg

Aggregate Results

Final