In his early years Dzeko had to struggle to be taken seriously. When he joined Zeljeznicar Sarajevo as a 13-year-old, he was dismissed as "Kloc", a nickname deriving from the slang term for a lamp-post.

Dzeko scored nine goals in the 2010 FIFA World Cup qualifying and finished as the second best scorer in UEFA qualification, tied with England's Wayne Rooney, both behind Greek striker Theofanis Gekas' 10 goals.