The Real Madrid goalkeeper has voiced his belief that the Euro 2008 and World Cup 2010 winners are looking good to retain their crown in Poland-Ukraine next year
Spain currently sit at the top of the table in Group I of the qualifying campaign for next year's European Championships and Casillas does not expect the reigning champions to experience any problems in the remaining three games as long as they remain humble.
Speaking to EFE ahead of his side's friendly clash with Italy in Bari, the 30-year-old said: "Spain are the favourites for Euro 2012 in my opinion. Of course, we have to be humble as we've always been.
"We can win another trophy if we treat approach the tournament with the respect it deserves. It's still a long road to the final though and it won't be easy."
Casillas moved on to discuss the 2014 World Cup and stated that Spain want to be successful in Brazil as well.
He added: "The qualification campaign for the 2014 World Cup hasn't started just yet, but we want to successful defend our title there [in Brazil] as well."
Spain are paired with France, Belarus, Georgia and Finland in Group I of the Uefa qualifying campaign for the tournament in South America.