The Zagreb tram network, run by the Zagrebački električni tramvaj (ZET), consists of 15 day and 4 night lines.

Trams operate on 116.3 kilometres (72.3 mi) of metre gauge route. During the day every line runs on average every 5–10 minutes, but almost every station serves at least two routes. Nighttime lines have exact timetables averaging at about every 40 minutes.

The first horsecar tram line was opened in 1891, and the first electric tram ran in 1910.

Zagreb's tram system transported 204 million passengers in 2008.