The 2003 Copa Nissan Sudamericana was the second edition of CONMEBOL's new international club tournament. It was won by Peruvian club Cienciano, who won the first international trophy for their club and the country. They also qualified to play in the 2004 Recopa Sudamericana.
|- !colspan="5"|Argentina III Preliminary
|- !colspan="5"|Argentina IV Preliminary
|- !colspan="5"|Venezuela Preliminary
|- !colspan="5"|Venezuela/San Lorenzo Preliminary
|- !colspan="5"|Bolivia Preliminary
|- !colspan="5"|Chile Preliminary
|- !colspan="5"|Peru Preliminary
|- !colspan="5"|Colombia Preliminary
|- !colspan="5"|Ecuador Preliminary
|- !colspan="5"|Paraguay Preliminary
|- !colspan="5"|Uruguay Preliminary
|- !colspan="5"|Quarterfinalist 4
|- !colspan="5"|Quarterfinalist 8
|- !colspan="5"|Quarterfinalist 2
|- !colspan="5"|Quarterfinalist 5
|-
|- !colspan="5"|Quarterfinalist 6
|- !colspan="5"|Quarterfinalist 1
|- |- !colspan="5"|Quarterfinalist 3
|- !colspan="5"|Quarterfinalist 7