As no candidate won an absolute majority of the vote in the first round, a second round of elections took place on 4 June 2017 between the two highest-placed candidates in terms of popular vote: incumbent mayor Milan Bandić of the Bandić Milan 365 - Labour and Solidarity Party and former Minister of Construction Anka Mrak Taritaš of the Croatian People's Party - Liberal Democrats.

As Zagreb, being the national capital, is the only Croatian city to enjoy a special status within Croatia's regional administrative framework (being both a city and a county), the mayor of Zagreb likewise also enjoys a status equal to that of a county prefect (Croatian: župan) of one of Croatia's other 20 counties (Croatian: županija).

Recent referendums The percentages of votes from each list are calculated from number of valid voters The percentages of valid and invalid votes are calculated from the turnout number The turnout percentage is calculated from the number of expected voters Poll results are listed in the tables below in reverse chronological order, showing the most recent first, and using the date the survey's fieldwork was done, as opposed to the date of publication.

The highest percentage figure in each polling survey is displayed in bold, and the background shaded in the leading party's color.

The lead column on the right shows the percentage-point difference between the two parties with the highest figures.