After good performances in his former club, he moved to most successful club of Uruguay, Peñarol in mid-2006. After a very good spell in the club, for example his nomination to the national team squad for the 2007 Copa América celebrated in Venezuela, among his achievements, in December 2007, was confirmed his move to Brazilian side Botafogo. Castillo signed a two-year contract with the club of Rio de Janeiro that will keep at the team until 2010.