Aldair subsequently moved to A.S. Roma in 1990 and played with this club during 13 seasons, until 2003. He played a total of 436 matches with the "Giallorossi", scoring 20 goals in total. During this period he won the Serie A in 2001, one Supercoppa Italiana, and one Coppa Italia in 1991 (also reaching the UEFA Cup Final in the same year). Aldair was recognised in 2000 as one of the best players in the world by being selected in the FIFA XI; still, he remained loyal to Roma in spite of the club not having won any major international honours during his time there.