[1] He captured a bronze medal in the 72-kg division at the 2003 World Taekwondo Championships in Garmisch-Partenkirchen, Germany, and attained top seven finishes in two editions of the Olympic Games (2000 and 2004), representing his naturalized nation Austria.

[3][4] Caliskan made his official debut, as part of his naturalized Austrian squad, at the 2000 Summer Olympics in Sydney, where he competed in the men's featherweight class (68 kg).

He crashed out in the opening match 3–7 to South Korean fighter and eventual silver medalist Sin Joon-sik, but mounted his strength to edge past Russia's Aslander Dzitiev (0–6) and then scored a 4–4 victory over Germany's Aziz Acharki upon the referees' decision in the repechage rounds.

[8][9] In his opening match, Caliskan trailed behind Central African Republic's Bertrand Gbongou Liango 1–4 in the third round, until he knocked his opponent unconscious with a roundhouse kick and dropped him face-down to the mat.

[10][11] In the quarterfinal match, Caliskan produced a pattern of aggressive attacks against Chinese Taipei's Huang Chih-hsiung on the final round, but his opponent responded to seal a 10–8 victory over him at the very end.