A football defender, Mariano Filho began playing professional football with Guarani FC, in 2005. Prior to this he was playing in the youth division of the same club. Filho remained with the club till 2006, during which time he made over 20 appearances with the team and scored once. In 2006 Filho moved to Ipatinga FC and remained there for one season, after which he moved to his current club Tombense in 2007.
Right after joining Tombense Filho was loaned out to Cruzeiro for one season, and then to Ipatinga for the next season. But in the middle of 2008, Filho was loaned out to Atletico-MG for the remaining season and he made 20 appearances for the club. In 2009 Filho was loaned out to Fluminense FC, where he currently plays.