In 1965, Sívori signed with Napoli, helping them to a third-place finish in the first season at the club; they also won the Coppa delle Alpi. After two successful seasons at the club, Napoli's squad during the 1967–68 season boasted several talents along with Sívori, such as goalkeeper Dino Zoff, and fellow strike partner José Altafini, and were considered one of the favourites to win the league title; the club took A.C. Milan all the way in the battle for the Serie A championship but eventually finished in second place, while Sívori was ruled out for most of the season due to a knee injury and several clashes with manager Bruno Pesaola. Ironically, Sívori's last game for Napoli was against his former club Juventus, in which he was given a red card for kicking Erminio Favalli, and was suspended for six matches. Following his ban, Sívori decided to return to Argentina during the 1968–69 season.