Zisis has also competed with Greece at the 2004 Summer Olympics, where Greece finished in 5th place in the world, and at the 2008 Summer Olympics, where Greece also finished in 5th place in the world. He also played at the following tournaments: the 2009 EuroBasket, where he won a bronze medal, the 2010 FIBA World Championship, the 2011 EuroBasket, the 2012 FIBA World Olympic Qualifying Tournament, the 2013 EuroBasket, the 2014 FIBA World Cup, and the 2015 EuroBasket.