Álex López Morón and Rafael Nadal defeated Todd Perry and Thomas Shimada in the final, 6–1, 6–3.
| Doubles | |
|---|---|
| 2003 Croatia Open | |
| 2002 Champions |  František Čermák  Julian Knowle |
| Champions |  Álex López Morón Rafael Nadal |
| Runners-up |  Todd Perry  Thomas Shimada |
| Score | 6–1, 6–3 |
František Čermák and Julian Knowle were the defending champions, but only Knowle competed that year partnering Lovro Zovko. They lost in the quarterfinals to López Morón and Nadal.
Seeds edit
Champion seeds are indicated in bold text while text in italics indicates the round in which those seeds were eliminated.
Massimo Bertolini / 
Tom Vanhoudt (semifinals)
Jaroslav Levinský / David Škoch (semifinals)
Julian Knowle / 
Lovro Zovko (quarterfinals)
Todd Perry / 
Thomas Shimada (final)
Draw edit
Key edit
- Q = Qualifier
- WC = Wild card
- LL = Lucky loser
- Alt = Alternate
- SE = Special exempt
- PR = Protected ranking
- ITF = ITF entry
- JE = Junior exempt
- w/o = Walkover
- r = Retired
- d = Defaulted
- SR = Special ranking
| First round | Quarterfinals | Semifinals | Final | ||||||||||||||||||||||||
| 1 |  M Bertolini T Vanhoudt
| 6 | 6 | ||||||||||||||||||||||||
 I Karlović A Kitinov
| 4 | 3 | 1 | M Bertolini T Vanhoudt
| w/o | ||||||||||||||||||||||
| D Ferrer F Vicente
| 6 | 6 | D Ferrer F Vicente
| ||||||||||||||||||||||||
| WC | M Marco Ripoll C Moyá
| 4 | 4 | 1 | M Bertolini T Vanhoudt
| 6 | 3 | 4 | |||||||||||||||||||
| 4 | T Perry T Shimada
| 6 | 78 | 4 | T Perry T Shimada
| 2 | 6 | 6 | |||||||||||||||||||
| ALT |  M Mertiňák L Svarc
| 3 | 66 | 4 | T Perry T Shimada
| 6 | 6 | ||||||||||||||||||||
| C Rochus O Rochus
| 6 | 3 | 6 | C Rochus O Rochus
| 4 | 4 | |||||||||||||||||||||
| ALT | R Karanušić M Radić
| 4 | 6 | 3 | 4 | Todd Perry Thomas Shimada
| 1 | 3 | |||||||||||||||||||
| Á López Morón R Nadal
| 6 | 6 | Álex López Morón Rafael Nadal
| 6 | 6 | ||||||||||||||||||||||
| D Hrbatý A Martín
| 4 | 3 | Á López Morón R Nadal
| 6 | 6 | ||||||||||||||||||||||
| WC |  N Smole M Tkalec
| 1 | 3 | 3 | J Knowle L Zovko
| 3 | 4 | ||||||||||||||||||||
| 3 | J Knowle L Zovko
| 6 | 6 | Á López Morón R Nadal
| 3 | 6 | 6 | ||||||||||||||||||||
| J I Carrasco R Ramírez Hidalgo
| 6 | 7 | 2 | J Levinský D Škoch
| 6 | 4 | 2 | ||||||||||||||||||||
 M Puerta A Schneiter
| 2 | 5 | J I Carrasco R Ramírez Hidalgo
| 6 | 4 | 3 | |||||||||||||||||||||
| E Artoni F Browne
| 4 | 5 | 2 | J Levinský D Škoch
| 3 | 6 | 6 | ||||||||||||||||||||
| 2 | J Levinský D Škoch
| 6 | 7 | ||||||||||||||||||||||||