|Men's Water Polo|
|Competitor for Spain|
|Gold||1996 Atlanta||Team Competition|
|Silver||1992 Barcelona||Team Competition|
|FINA World Championships|
|Gold||1998 Perth||Team Competition|
|Silver||1991 Perth||Team Competition|
|Silver||1994 Rome||Team Competition|
|FINA World Cup|
|Bronze||1985 Duisburg||Team Competition|
|Bronze||1991 Barcelona||Team Competition|
|Bronze||1999 Sydney||Team Competition|
|Silver||1991 Athens||Team Competition|
|Bronze||1993 Sheffield||Team Competition|
Estiarte has played 578 times for the Spain national team.
With the national squad he reached the finals at the 1992 Barcelona Olympics on home soil. Estiarte converted a penalty 42 seconds from full time to put Spain ahead, but nine seconds later Italy equalised and went on to win 9-8 in extra time.
Four years later, he was part of the team that made up for this painful loss by winning gold in the 1996 Atlanta Olympics, defeating Croatia 7-5 in the final. The 1996 tournament was the only one of his six Olympics when Estiarte was not the tournament's top scorer
Estiarte is the second Spaniard to compete at six Olympic Games, after equestrian Luis Álvarez de Cervera. As of 2012, no other Spaniards have competed in six Olympics.
Estiarte is the first water polo player to compete at six Olympic Games. (While there is a case for Welshman Paul Radmilovic to be recognized as such, one of his appearances was the 1906 Intercalated Games, which are not considered 'official'.)