Soon after Zambrotta was brought to Serie A, he gained the attention of the Italian national side. He was selected to play for the Italy under-21 national team for the first time on 25 March 1998 against Malta. In his second game for the U21, against Wales on 22 April 1998, he scored the second goal for Italy on the 43rd minute and helped Italy to win 2–1. In 1998, he played in all six games of the Italy U21 while they won five of them and drew the last one against Spain.