After five seasons in the Spanish league, Zamorano played four seasons in Serie A with Inter Milan, from 1996 to 2000, where he was teammates with Youri Djorkaeff, Diego Simeone, Javier Zanetti, and Ronaldo, among others. He was initially the club's premier striker, holding the coveted number nine shirt. However, upon Baggio's arrival at the club, Ronaldo was forced to give up number ten, and wear number nine, therefore Zamorano had to give up his number but refused to wear another and started wearing a shirt bearing the number '1+8', therefore making him mathematically still a number 9 striker. In May 1998, Inter won the UEFA Cup after beating Lazio in the final 3–0, with Zamorano scoring the opening goal. He had also scored in second leg of the previous year's final, with the game going to penalties. However, Zamorano missed his penalty as Inter lost to Schalke 1–4.