After a string of impressive displays in the Champions League, Carew moved to Spanish club Valencia in an €8.5 million transfer, where he managed to win the La Liga title twice. Carew was part of the Valencia side that lost on penalties in the 2001 UEFA Champions League Final, though he scored his own penalty attempt. His goals in the campaign were crucial, including a 75th-minute header in a 1–0 home win against Arsenal in the second leg of the quarter-final, which saw Valencia advance to the semi-final. In the 2002–03 Champions League campaign, Carew was once again responsible for Arsenal's exit from the competition. With Valencia needing a win in their final game of the second group phase at home against Arsenal to progress to the quarter finals, Carew scored twice in a 2–1 victory. He then spent the 2003–04 season on loan at Italian side Roma where he scored 7 goals in 26 games.