The protesters accuse Vucic of stifling hard-won democratic freedoms in the Balkan country that was involved in a series of wars during the 1990s. He denies the accusation.
Braving freezing temperatures, the president's critics blocked traffic in the center of Belgrade as they marched by the state TV building and toward the government headquarters on Saturday.
The organizers want Vucic to ease what they say is a tight grip on Serbian media. He is a former extreme nationalist who now says he wants Serbia to join the European Union.
The protests started after thugs beat up an opposition politician in November.