Known by his widely used nickname Zeka, he is most notable as the controversial and all powerful general-secretary of FK Partizan, a role he performed for more than two decades.

Born to father Slavko Zečević [sr] (former Police Minister and former FK Partizan managing board member) Žarko's entire sports career, both playing and administrative, is also tied to Partizan Sports Society.

During the late 1960s and 1970s, he was a basketball player for KK Partizan and even managed 16 appearances in the Yugoslavia national basketball team jersey, though only in friendly preparation games and minor competitions - he never made the final cut for any of the major competitions (Eurobasket, World Championships, and the Olympics).

Žarko Zečević was married to Mira who used to work as marketing director at Politika daily newspaper during the 1990s.

Zečević's sister is married to Danko Đunić, former Partizan Sports Society president.