# Swimming at the 2003 World Aquatics Championships – Men's 4 × 100 metre medley relay

The Men's 4×100 Medley Relay event at the 10th FINA World Aquatics Championships swam on 27 July 2003 at the Palau Sant Jordi in Barcelona, Spain. Preliminary heats swam during the day's morning session, with the top-8 teams advancing to swim again in a Final heat in the day's evening session.
At the start of the event, the existing World (WR) and Championship (CR) records were:
* WR: 3:33.48 swum by the USA on August 29, 2002, in Yokohama, Japan
* CR: 3:35.35 swum by Australia on July 28, 2001, in Fukuoka, Japan

## Results
### Final

| Rank | Lane | Nation | Swimmers | Time | Notes |
| 1 | 4 | USA | Aaron Peirsol (53.71) Brendan Hansen (59.61) Ian Crocker (50.39) Jason Lezak (47.83) | 3:31.54 | WR |
| 2 | 6 | Russia | Arkady Vyatchanin (54.87) Roman Ivanovski (1:00.18) Igor Marchenko (51.72) Alexander Popov (47.95) | 3:34.72 | |
| 3 | 5 | Japan | Tomomi Morita (54.93) Kosuke Kitajima (59.11) Takashi Yamamoto (52.24) Daisuke Hosokawa (49.84) | 3:36.12 | |
| 4 | 3 | France | Simon Dufour (55.53) Hugues Duboscq (1:00.12) Franck Esposito (52.04) Frédérick Bousquet (48.70) | 3:36.39 | |
| 5 | 7 | Netherlands | Klaas-Erik Zwering (56.56) Thijs van Valkengoed (1:01.67) Joris Keizer (52.19) Pieter van den Hoogenband (46.70) | 3:37.12 | |
| 6 | 2 | Ukraine | Volodymyr Nikolaychuk (55.95) Oleg Lisogor (1:00.35) Andriy Serdinov (51.30) Vyacheslav Shyrshov (49.68) | 3:37.28 | |
| 7 | 1 | Canada | Riley Janes (55.39) Morgan Knabe (1:01.04) Mike Mintenko (52.23) Brent Hayden (49.28) | 3:37.94 | |
| 8 | 8 | Great Britain | Gregor Tait (55.40) James Gibson (59.80) Todd Cooper (53.91) Chris Cozens (49.10) | 3:38.21 | |

### Preliminaries

| Rank | Heat/Lane | Nation | Swimmers | Time | Notes |
| 1 | H4 L4 | United States | Randall Bal, Ed Moses Michael Phelps, Neil Walker | 3:34.80 | q, CR |
| 2 | H4 L3 | Japan | Tomomi Morita, Kosuke Kitajima Takashi Yamamoto, Daisuke Hosokawa | 3:37.08 | q |
| 3 | H3 L3 | France | Simon Dufour, Hugues Duboscq Franck Esposito, Frédérick Bousquet | 3:37.57 | q |
| 4 | H2 L4 | Russia | Evgueni Alechine, Dmitry Komornikov Evgueni Korotychkine, Denis Pimankov | 3:38.14 | q |
| 5 | H3 L5 | Ukraine | Volodymyr Nikolaychuk, Oleg Lisogor Andrii Serdinov, Vyacheslav Shyrshov | 3:38.50 | q |
| 6 | H4 L1 | Netherlands | Klaas Erik Zwering, Thijs van Valkengoed Joris Keizer, Pieter van den Hoogenband | 3:38.81 | q |
| 7 | H2 L3 | Canada | Riley Janes, Morgan Knabe Mike Mintenko, Brent Hayden | 3:39.41 | q |
| 8 | H4 L6 | Great Britain | Gregor Tait, James Gibson Todd Cooper, Chris Cozens | 3:39.80 | q |
| 9 | H2 L5 | Hungary | Péter Horváth, Károly Güttler Zsolt Gáspár, Attila Zubor | 3:39.83 | |
| 10 | H4 L7 | Slovenia | Blaž Medvešek, Emil Tahirovič Peter Mankoč, Jernej Godec | 3:40.79 | |
| 11 | H4 L5 | Germany | Toni Helbig, Mark Warnecke Johannes Dietrich, Torsten Spanneberg | 3:41.33 | |
| 12 | H2 L6 | Finland | Jani Sievinen, Jarno Pihlava Tero Välimaa, Matti Rajakylä | 3:41.49 | |
| 13 | H3 L6 | Sweden | Jens Petersson, Martin Gustavsson Lars Frölander, Stefan Nystrand | 3:42.63 | |
| 14 | H4 L8 | Lithuania | Darius Grigalionis, Vytautas Janušaitis Rimvydas Šalčius, Paulius Viktoravičius | 3:43.63 | |
| 15 | H4 L2 | Croatia | Gordan Kožulj, Vanja Rogulj Krešimir Čač, Igor Čerenšek | 3:43.73 | |
| 16 | H3 L2 | China | Ouyang Kunpeng, Haibo Wang Hao Jin, Zuo Chen | 3:43.80 | |
| 17 | H2 L2 | Brazil | Paulo Machado, Eduardo Fischer Kaio Almeida, Gustavo Borges | 3:44.61 | |
| 18 | H3 L7 | Switzerland | Karel Novy, Remo Lutolf Philipp Gilgen, Dominik Meichtry | 3:45.76 | |
| 19 | H1 L4 | Estonia | Martin Viilep, Vladimir Labzin Ken Tomson, Danil Haustov | 3:52.49 | |
| 20 | H3 L8 | Hong Kong | Yau Sun Fai, Chi Kin Tam Shui Ki Szeto, Kin Lun Doo | 3:57.51 | |
| 21 | H1 L3 | Macau | Chi Lon Lei, Chan Wai Ma Wing Cheung Victor Wong, Kuan Fong Lao | 4:04.45 | |
| 22 | H1 L6 | Nigeria | Olufolahan Oluwole, Eric Williams Musa Bakare, Gentle Offoin | 4:09.17 | |
| - | H2 L1 | South Africa | Gerhard Zandberg, Chris Stewart Roland Schoeman, Ryk Neethling | DQ | |
| - | H3 L4 | Australia | Josh Watson, Jim Piper Adam Pine, Ian Thorpe | DQ | |
| - | H3 L1 | Algeria | Raouf Benabid, Sofiane Daid Aghiles Slimani, Salim Iles | DQ | |
| - | - | Italy | | DNS | |
| - | - | Uzbekistan | | DNS | |
| - | - | Cote d'Ivoire | | DNS | |