With Italy's junior national teams, he played at the 2007 FIBA Europe Under-16 Championship and the 2008 FIBA Europe Under-18 Championship.
Europe | 2007 | 2007 in music | World Rally Championship | Eastern Europe | Central Europe | World Championship | NCAA Men's Division I Basketball Championship | Ultimate Fighting Championship | World Championship Wrestling | Council of Europe | 2007 Cricket World Cup | Australian federal election, 2007 | 2007 Pan American Games | Organization for Security and Co-operation in Europe | Western Europe | World Touring Car Championship | Six Nations Championship | County Championship | British Touring Car Championship | World Chess Championship | United Nations Economic Commission for Europe | national championship | All-Ireland Senior Hurling Championship | Football League Championship | Extreme Championship Wrestling | Europe 1 | Bowl Championship Series | Championship | All-Ireland Senior Football Championship |
Also in 1977, at Cagnes-sur-Mer, he won the World Under-16 championship (ahead of other distinguished young talents, including Garry Kasparov), before becoming Icelandic champion on the first of three occasions (1977, 1982 and 1988).
Giannakis led the Greek junior national team to the silver medal at the FIBA Europe Under-16 Championship of 1975.
Shahid Dastgerdi Stadium along with Rah Ahan Stadium hosted the 2012 Asian under 16 Championship.