BBC Sport Online looks back at their remarkable achievements in the Champions League.
Valencia 3-0 Leeds
Leeds' Champions League dream came to a crashing end in a tension-filled semi-final second leg at the Mestalla Stadium. Valencia's Juan Sanchez scored twice in a 3-0 win which saw Alan Smith sent off in the dying minutes of the game, as Leeds' frustration reached boiling-point.
real 14k Click here to hear BBC Sport's Alan Green's match report.
real 14k Click here to hear David O'Leary's post-match comments.
real 14k Click here to hear Erik Bakke's comments after the match.
real 56k Click here to watch Leeds defender Rio Ferdinand's comments after the match.
real 56k Click here to see Leeds' Harry Kewell's post-match views.
real 56k Click here to watch Leeds' Olivier Dacourt.
Leeds United 0-0 Valencia
Leeds are held to a 0-0 stalemate at Elland Road against a disciplined Valencia. United had chances to secure a precious lead in the semi-final first leg with a vibrant second half performance that tested last year's beaten finalists to the limit.
real 14k Click here to hear BBC Sport's Alan Green's match report.
real 14k Click here to hear Leeds United boss David O'Leary's reaction.
real 14k Click here Leeds United's Rio Ferdinand's post-match views.
real 14k Click here to hear Olivier Dacourt's assessment of Leeds' performance.
real 14k Click here to hear how Valencia striker John Carew views the outcome.
Deportivo La Coruna 2-0 Leeds
Leeds progress in the Champions League despite suffering a battering from the Spanish champions Deportivo La Coruna.
David O'Leary's side were forced to defend doggedly after goals from Djalminha and substitute Tristan gave the Spaniards a glimmer of hope.
real 14k Listen to BBC Sport's Ron Jones' match report.
real 14k Listen to Leeds' Lee Bowyer describe his reaction to their victory.
real 14k Listen to Leeds chairman Peter Risdale explain the significance of the result to the club.
Leeds 3-0 Deportivo La Coruna
It was another brilliant European night for Leeds as they overcame Spanish giants Deportivo La Coruna, running out 3-0 winners. A thumping free-kick from Ian Harte and goals from Alan Smith and Rio Ferdinand capped a glorious night.
real 14k Listen to BBC Sport's John Murray's match report.
real 14k Click here to hear Leeds boss David O'Leary's thoughts.
real 14k Click here to listen to goal scorer Rio Ferdinand's interview.
real 14k Listen to Deportivo striker Roy Makaay's views on the game.Leeds 3-3 Lazio
Leeds came from behind twice in the first half in an exuberant and occasionally heated encounter. Mark Viduka looked to have settled matters with a header after the break, but Mihajlovic scored a brilliant free-kick to add a point to Lazio's tally.
real 14k Listen to BBC Sport's John Murray's match report.
real 14k Listen to Leeds United striker Mark Viduka's post-match comments.
Real Madrid 3-2 Leeds
A brave effort by Leeds saw an early Alan Smith goal put them ahead only to lose 3-2 to Real Madrid at the Bernabeu. The first of Real's goals looked a blatant handball that went unnoticed by the match officials.
real 14k Listen to BBC Sport's John Murray's match report.
real 14k Listen to Leeds United boss David O'Leary's post-match views.
real 14k Listen to Leeds defender Rio Ferdinand's post-match verdict.
In an outstanding performance, Alan Smith scored either side of a Mark Viduka header. Anderlecht's Jan Koller sparked brief hopes of a comeback but Ian Harte's 80th minute penalty sealed Leeds quarter-finals berth.
real 14k Listen to BBC Sport's Ian Brown's match report.
real 14k Listen to Leeds United boss David O'Leary's post-match views.
real 14k Listen to Leeds striker Mark Viduka's post-match verdict.
Leeds United 2-1 Anderlecht
David O'Leary's side fell behind to a well worked goal from Alin Stoica, but Ian Harte rifled home a spectacular 30-yard free-kick before Lee Bowyer set the stadium alight with a stunning goal four minutes from time.
real 14k Listen to BBC Sport's Alan Green's match report.
real 14k Listen to Leeds United defender Rio Ferdinand's post-match views.
Lazio 0-1 Leeds United
An Alan Smith goal after a moment of brilliance from Mark Viduka gives Leeds all three points as they produce a superb performance against Lazio in Rome.
real 14k Listen to BBC Sport's Steve Wilson's match report.
real 14k Listen to Leeds United boss David O'Leary's post-match views.
Leeds United 0-2 Real Madrid
Leeds battle gamely but the class of Real Madrid tells in the end. Two goals in as many second-half minutes see the Spanish side seal victory at Elland Road.
real 14k Listen to BBC Sport's Alan Green's match report.
real 14k Listen to Leeds United's Gary Kelly's post-match views.
AC Milan 1-1 Leeds United
A crucial game as Leeds need a draw to ensure qualification. Dominic Matteo provides the break through with a goal just before half-time and Leeds manage to keep Milan at bay long enough to force a draw.
real 14k Listen to BBC Sport's Ian Brown's match report.
Leeds United 1-1 Barcelona
Formidable opposition but Leeds deliver the goods. Lee Bowyer strikes early on to put Leeds ahead. Rivaldo spoils the party in the dying seconds of injury time by grabbing an equaliser.
real 14k Listen to BBC Sport's Alan Green's match report.
Besiktas 0-0 Leeds United
A return to Turkey for Leeds sees high security and dire warnings to the Leeds fans. However, the match ends up in a well-behaved draw.
real 14k Listen to BBC Sport's John Murray's match report.
Leeds United 6-0 Besiktas
Leeds' growing confidence shows with a stunning victory over the Turkish side. The Elland Road crowd are treated to a goal fest with 5 players scoring, including new-boy Matteo.
real 14k Listen to BBC Sport's Ian Brown's match report.
real 14k Listen to David O'Leary's post-match views.
Leeds 1-0 AC Milan
Leeds beat Italian giants AC Milan thanks to a goalkeeping error. Lee Bowyer's shot sneaks in and delights the Elland Road faithful in the dying minutes of the match.
real 14k Listen to BBC Sport's Ian Brown's match report.
Barcelona 4-0 Leeds United
Leeds United begin their European campaign disastrously. David O'Leary's young side are missing several key players and are torn apart by a rampant Barcelona side.
real 14k Listen to BBC Sport's Ian Brown's match report.
real 14k Listen to Leeds boss David O'Leary's post-match reaction.