Castillo first won medals in the 2004 Pan American Championships and the Leonding Tournament in Austria.

That year she also participated in the 2007 World Championships in Rio de Janeiro, Brazil.

Castillo's greatest result was in the 2008, where Castillo won a silver medal in the ‍–‍78 kg category at the 2008 Summer Olympics in a disputed match against the local contender Yang Xiuli.

During 2008 she also won the Torneo de Cuenca in Ecuador, the Tre Torri in Italy, the Super Cup of the World, in Hamburg, Germany, and the 2008 Pan American Championships in Miami, USA.

Castillo was intermittently in and out of international competition due to an injury and because she married Cuban baseball player Frank Morejón and had a child.