He captured the men's singles title at the French Open in 2003, and in October that year he became the 21st player to hold the World No. 1 ATP singles ranking. He has also been a runner-up at two other Grand Slams during his career. His nickname is "Mosquito" due to his speed and wiry, strong physique.

Came to prominence in 1998 making final of the Roland Garros juniors losing to Fernando Gonzalez finishing the year ranked number 17 junior.

Ferrero made his professional debut in 1999, making an immediate splash by reaching the semi-finals of his first tour event in Casablanca. He made his Grand Slam debut at the US Open in August and then in the following month, in only his fifth professional event, he won his first career title in Mallorca.

Ferrero continued his rise throughout 2000 and although he did not win a title, he reached finals in Dubai and Barcelona and helped Spain win the Davis Cup by defeating Lleyton Hewitt and Patrick Rafter in the final against Australia. His best performance however was arguably at his first French Open, where he stormed to the semi-finals, losing only to eventual champion Gustavo Kuerten in five sets.

In 2001 Ferrero confirmed his status as one of the game's best clay court players, winning titles in Estoril, Barcelona and Rome, and he reaching the semi-finals at the French Open for the second consecutive year, losing again to Gustavo Kuerten. Ferrero also won the tour event in Dubai, and finished the year ranked five in the world.

2002 saw Ferrero reach his first Grand Slam final at the French Open. However, despite being the strong favourite, he lost to compatriot Albert Costa in four sets. He won titles in Monte Carlo and Hong Kong and reached the final of the Tennis Masters Cup in Shanghai, losing a five set final to Lleyton Hewitt. This result saw the Spaniard finish the year ranked fourth in the world.

2003 saw Ferrero have his best year to date, winning the titles in Monte Carlo and Valencia before fulfilling his clay court promise by taking the French Open, easily defeating Dutchman Martin Verkerk in the final. He also went on to reach the final on the hard courts at the US Open, eliminating the likes of Lleyton Hewitt and Andre Agassi before going down to Andy Roddick. This result saw Ferrero become the number one ranked player in the world. He rounded the year off by taking his first indoor title in Madrid and was presented with a "National Sportsman of the Year" award from King Juan Carlos. He would end the year ranked No. 3 in the world.

Injuries however began to plague Ferrero throughout 2004 and his ranking and form dipped. Despite making the Australian Open semifinals early in the year (losing to Roger Federer), chicken pox kept him out for the entire month of March and after a first round loss in Monte Carlo in April, he required another month out for rest and recuperation. On May 8 Ferrero fell during a practice session, injuring his ribs and his right wrist and went into the defence of his French Open crown underprepared. He lost in the second round to Igor Andreev and continued to struggle for the rest of the year, finishing outside the world's top 30 for the first time in five years.

Ferrero looked fresher and healthier in 2005 and began to climb back up towards the top echelons of the game. He reached the semifinals of the Monte Carlo Masters and the finals of the Open Seat Godo in Barcelona in April, as well as the finals of Vienna later in the year. He ended 2005 ranked #17.

Despite being a former world number one, Ferrero has a poor record at Wimbledon, and is unknown to many casual fans in the United Kingdom (who tend to only watch around the Wimbledon period).

Ferrero's inspiration is his mother who died from cancer when he was 17.