Following his full international debut at the senior level on 3 June 2000 against Sweden (at 19 years and 14 days), Casillas was an unused substitute at UEFA Euro 2000.
Pas debutimit me kombëtaren kundër Suedisë më 3 qershor 2000 (19 vjeç e 14 ditë), Casillas ishte një zëvëndësim i papërdorur në Euro 2000.