In 2004, he signed with CR Vasco da Gama and was immediately loaned back to Olaria for that year's Carioca.
[3] Cássio only became a regular starter in the 2006 season, playing 35 Série A games to help his team to sixth place.
[9] Cássio did not miss a minute of action in 2012–13,[10] as Paços finished a best-ever third and qualified for the UEFA Champions League for the first time in its history.
[11] After leaving the Estádio da Mata Real, Cássio continued to play in the Portuguese top division, for F.C.
[14] On 9 June 2018, the 38-year-old Cássio signed a one-year deal with Saudi Professional League club Al Taawoun FC as a replacement for Essam El Hadary, seven years his senior.