In 2003, Ferrero started the year by reaching the finals in the Adidas International, losing to Hyung-Taik Lee, 6–4, 6–7(6–8), 6–7(4–7). He went on to reach the quarter–finals of the Australian Open, losing to Wayne Ferreira, 6–7(4–7), 6–7(5–7), 1–6. He then competed for Spain at Davis Cup against Belgium and won both his matches against Christophe Rochus 6–3, 6–2, 7–5 and Kristof Vliegen 6–1, 6–4. He then competed at the ABN AMRO World Tennis Tournament but retired with a sprained ankle in the quarterfinals against Raemon Sluiter while leading 2–1 in the first set. At the next two Masters events of Pacific Life Open and NASDAQ–100 Open, he lost in the round of 32 to Brian Vahaly 4–6, 6–3, 3–6 and to Marcelo Ríos 3–6, 6–7(2–7). In the quarterfinals of Davis Cup against Croatia, he won his only match against Mario Ančić 6–4, 6–2, 7–6(7–1).