At the Swedish Open reached the quarterfinals, losing to Jarkko Nieminen 6–7(5–7), 2–6. He then fell early at the first round of Croatia Open Umag to Albert Portas and second round of Rogers Cup to Fernando González 2–6, 1–6. He reached his lone final of the year at the Western & Southern Financial Group Masters, Ferrero notched his first top 10 win of 2006 with a 6–2, 6–4 win over US No. 1 and No. 5 player James Blake. A few days later, Ferrero defeated No. 2 Rafael Nadal, 7–6(7–2), 7–6(7–3), and subsequently No. 7 Tommy Robredo, 6–3, 6–4, to move into the final of an ATP Masters Series event for the first time since 2003. In the final, Ferrero lost to Andy Roddick, 3–6, 4–6. Ferrero ended the year with a five match losing streak, beginning with the second round of the US Open to Marc Gicquel 5–7, 3–6, 4–6. This was followed by loses in his first matches at the PTT Thailand Open to Mischa Zverev 6–4, 2–6, 4–6, at the Open de Moselle to Julien Benneteau 4–6, 6–1, 6–7(7–9), at the BA–CA–TennisTrophy to Jürgen Melzer 7–5, 6–7(5–7), 3–6, and at the Mutua Madrileña Madrid Masters to Robin Söderling 3–6, 2–6. He ended the year ranked No. 23.