He represented mainly Las Palmas and Betis during his career, appearing in 282 matches in La Liga and 435 in Segunda División (scoring an all-time best 195 goals in the latter competition).

[4] In the 2003–04 campaign he was crowned Pichichi Trophy of the Segunda División for his hometown club, netting 22 times – with the team being nonetheless relegated – and being subsequently purchased by Depor.

During the January transfer window another loan happened, this time to Catalonia's Gimnàstic de Tarragona where he started very well with three goals in his first three matches,[6] although the side would be eventually relegated and the player returned to Deportivo.

[10] The attacking trio of himself, Jorge Molina and midfielder Achille Emaná combined for more than 50 league goals in 2010–11, as the Andalusians returned to the top tier after two years of absence.

[13] On 10 December 2011, Castro put a stop to a streak of 11 games without one win for the Pepe Mel-led side with only one point managed, netting twice in stoppage time of the 2–1 home victory over Valencia CF.

[17] In July 2017, aged 36, Castro moved abroad for the first time in his career, being loaned to Chinese Super League club Guizhou Hengfeng Zhicheng F.C.

[18] In his first match upon his return to the Estadio Benito Villamarín, on 15 January 2018, he replaced Sergio León late into the home fixture against CD Leganés and scored the 3–2 winner through a penalty.