As a manager, his most successful period was with the Croatia national team, which he led to the quarter-finals in the 1996 European Championship and won third place at the 1998 FIFA World Cup. He also managed the following national teams: Switzerland, Iran, Bosnia and Herzegovina and China Olympic. Blažević also had successful spells at FC Vevey, FC Sion, FC Lausanne-Sport, HNK Rijeka, GNK Dinamo Zagreb, Grasshopper Zürich, FC Prishtina, NK Osijek, NK Varteks, NK Zagreb, Shanghai Shenhua and FK Sloboda Tuzla.