In the summer of 2003, Luisão moved to Europe to sign with Portuguese club Benfica for a £890,000 transfer fee paid by the Lisbon-based side. He faced a tough period of adaptation, during which time he performed somewhat below his capabilities and even considered traveling back to his home country. However, he managed to score in his league debut, a 3–3 home draw against C.F. Os Belenenses on 14 September. He ended his first season winning the Taça de Portugal after Benfica defeated fierce rivals FC Porto 2–1 in the tournament final.