Bandić started his political career in 1983 by working in the Peščenica municipality. He rose to prominence in the 1990s as the leader of the Zagreb branch of the Social Democratic Party of Croatia (SDP). Following SDP's victory in the 2000 local elections, he was elected mayor by the Zagreb Assembly, ending a decade of Croatian Democratic Union (HDZ) rule, and was re-elected in 2001. He resigned in 2002 due to his involvement in a car accident, but remained deputy mayor. He returned to the mayoral position after the SDP won the 2005 elections. Bandić was both a prominent force within and one of the most popular members of the SDP.